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Full text of "The prevention of malaria in the Federated Malay States : a record of twenty years' progress"

THE PREVENTION OF MALARIA 

IN THE 

FEDERATED MALAY STATES 



THE PREVENTION OF MALARIA IN 
THE FEDERATED MALAY STATES 




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[FroHfispiece. 



THE 

PREVENTION OF MALARIA 

IN THE FEDERATED MALAY STATES 

A RECORD OF TWENTY YEARS' PROGRESS 



MALCOLM WATSON, M.D., CM., D.P.H. 

Chief Medical Officer, Estate Hospital's Association, Klang, F.M.S. ; 

late Senior District Surgeon, F.M.S. Medical Service ; author of 

" Rural Sanitation in the Tropics," etc. 

WITH CONTRIBUTIONS BY 

P. S. HUNTER, M.A., M.B., D.P.H. 

Deputy Health Officer, Singapore 
AND 

A. R. WELLINGTON, M.R.C.S., L.R.C.P., D.P.H., D.T.M.&H. 

Senior Health Officer, Federated Malay States 
AND A PREFACE BY 

SIR RONALD ROSS, K.C.B., K.C.M.G. 
F.R.C.S., D.P.H., M.D., LL.D., D.Sc, F.R.S., Nobel Laureate 



SECOND EDITION— REVISED AND ENLARGED 



NEW YORK 

E. P. DUTTON AND COMPANY 

1 92 1 



Heel U> 
MM 4 

.W5.9 



DEDICATED 
BY PERM ISSION 

TO 

SIR FRANK ATHELSTANE SWETTENHAM 
G. C. M. G. 



LIST OF CONTRIBUTORS TO THE PUBLICATION 
OF THE FIRST EDITION OF THIS BOOK 

The Anglo-Malay Rubber Company, ii Idol Lane, London, E.C. 

The Highlands and Lowlands Rubber Company, Ceylon House, 
Eastcheap, E C. 

The Chersonese Rubber Company, Ceylon House, Eastcheap, 
London, E C. 

The Linggi Rubber Company, 5 Whittington Avenue, London, EC. 

The Selangor Rubber Company, 124 St Vincent Street, Glasgow. 

The Penang Sugar Estates, Limited, E. L. Hamilton, Esq., 27 
Austin Friars, London. 

The Rubber Estates of Johore, ii Idol Lane, London, E.C. 

The Johore Rubber Lands, 16 Philpot Lane, London, E.C. 

The Rubber Plantations Investment Trust, ii Idol Lane, 
London, E.C. 

The Golconda Rubber Company, 2 Fenchurch Avenue, London, E.C. 

Messrs Gow, Wilson, and Stanton, 13 Rood Lane, London, E.C. 



PREFACE TO THE FIRST EDITION 
By SIR RONALD ROSS 

Towards the end of last year, I asked Dr Malcolm Watson 
to contribute an article to my book on the Prevention of 
Malaria regarding his work in the Federated Malay States. 
Unfortunately, the article which he sent to me, though 
interesting from beginning to end, was too long to be inserted 
with the contributions furnished by nineteen other workers in 
various parts of the world : and I therefore determined to try 
to publish his paper as a separate book. We are greatly 
indebted to Sir Frank Swettenham, G.C.M.G., the distinguished 
organiser of Federal Administration in the Protected Malay 
States, for the assistance which he gave us in this respect. 
Mr H. J. Read, C.M.G., of the Colonial Office, was kind enough 
to approach him on my behalf regarding the matter ; and the 
result was that the various Companies mentioned on a previous 
page generously provided the necessary funds. Not only Dr 
Watson and myself owe our thanks to Sir Frank Swettenham 
and to these Companies for the help given to us, but I think 
that the Governments and peoples of many malarious countries 
will be not less grateful. 

The time is one of change and advancement in our ideas of 
colonial development. We are passing away from the older 
period of incessant wars and of great military or civil dictator- 
ships into one of more minute and scientific administration in 
which the question always held before us is : What can best be 
done for increasing the prosperity of the people ? Sanitation is 
almost the first word in the answer. Prosperity is impossible in 
the face of widespread disease, and perhaps the very first effort 



x PREFACE TO THE FIRST EDITION 

which must be made in new countries is to render them 
reasonably safe, not only from human enemies, but from those 
small or invisible ones which in the end are so much more 
injurious. As one example of this new theorem I can quote 
that of Panama, where the Americans began their great work 
by laborious sanitary preparations. Another example will be 
found in this book. 

The author describes the origin of the Federated Malay 
States and the great sanitary problem which remained when 
that Federation was completed. It is a picture of a great work 
and of a great difficulty beyond it. Political adjustments are 
not everything, and for additional successes the statesman must 
be followed by the man of science and the scientific adminis- 
trator. Possessed of great natural riches, of an intelligent 
population, and of neighbouring sources of intelligent labour, 
the States appeared from the first to have been designed for 
wealth and success. Within them, however, there lived a 
relentless enemy- — a disease which hampers all human work, 
especially that of the pioneer and the planter, to a degree 
which will scarcely be believed in this country ; and the task 
before the Government was to subdue this enemy if possible. 
I have said elsewhere that the Panama Canal is being dug with 
a microscope, and I believe that the same instrument will 
double the wealth of the Federated Malay States. 

Technically, Dr Watson's book is of the utmost value to all 
workers against malaria. He has laboured at his campaign for 
eight years ; he has studied the disease from every point of 
view, and its prevention by every method. He has attacked it 
in towns, in villages, and in plantations ; and has thrown into 
the work a degree of energy and enthusiasm which has not 
been exceeded in any anti-malaria campaign which has been 
carried out since we learned the manner in which it is carried 
from man to man. This book contains the details of his 
methods and the lessons which he has to teach. I may, 
perhaps, be allowed the privilege of considering it to be a part 
of my own work mentioned above. 



PREFACE TO THE FIRST EDITION xi 

More than ten years have now elapsed since we learned 
how the disease is carried. This has been a period of proba- 
tion, during which many methods of prevention have been 
tentatively investigated. We have had great examples of 
success by various methods in the Panama Canal Zone, in 
Italy, in Ismailia, and in many other places ; but I trust that 
this book, which describes the no less brilliant campaign of 
the Federated Malay States, will furnish the Governments, the 
health departments, and the planters of every malarious 
country with detailed information which they can always use for 
similar work ; and we may now hope that progress will become 
still more rapid and complete in the future. 

Ronald Ross. 

University of Liverpool, 
ist December 1910. 



AUTHOR'S PREFACE TO THE 
SECOND EDITION 

Within a few months of its publication by the Liverpool 
School of Tropical Medicine in 191 1, the first edition of this 
book was sold out. A reprint was suggested, but as our 
knowledge at that time was increasing rapidly, I felt the book 
should be re-written. 

Visits to Sumatra, Panama, and British Guiana, the 
writing of Rural Sanitation in the Tropics, and the war, have 
all served to delay the issue of a new edition ; but another, 
and perhaps the chief cause, was a disinclination to write 
during the progress of many anti-malaria schemes, and before 
they had reached fruition — in other words, a dislike to write 
of uncompleted work. 

Whatever hesitation there may be elsewhere, mosquito 
reduction, as the method of stamping out malaria, has been 
so widely adopted throughout Malaya that each year always 
leaves work unfinished, as it also initiates new work, and sees 
the completion of what was begun in former years. But, how- 
ever fascinating it is to gather in one harvest, and to look 
forward to the next, the need of the new workers for guidance 
is too great to allow of further delay in publishing. 

Sir Ronald Ross pointed out in the first chapter of his 
Prevention of Malaria, that the work described in the first 
edition of this book recorded a new phase in anti-malarial 
work, namely the control of malaria by anopheline reduction 
in rural areas. From small beginnings in towns, the work 
has spread in ever-widening circles, and, I might add, in spite 
of an apparently ever-deepening complexity of the problem. 



xiv AUTHOR'S PREFACE TO THE SECOND EDITION 

So far from the map of Malaya being evenly washed with the 
malarial taint, violent contrasts have been found in different 
parts, and widely different, often diametrically opposed, 
methods have been found necessary for its control. Some 
land, when covered with jungle, has been found to be malarial, 
and some non-malarial ; some land has become healthy when 
cleared of jungle, and some has become intensely malarial 
when so treated ; drainage frees some land from malaria, but 
some remains malarial ; some land is malarial whether drained 
or undrained, whether under jungle or cleared of jungle ; some 
rice fields are malarial, and some are non-malarial ; while in a 
single ravine, the various insect inhabitants may come and go 
in the wondrous fashion of a fairy tale. In their stories of 
the little Mouse-deer, the Malays have invented a " Puck," 
who plays endless tricks on the other creatures of the forest. 
Sometimes I suspect he has been working his wiles on men 
and mosquitoes, and, uninvited, been taking an elfish interest 
in mosquito control, which we could gladly have excused. 

Through the maze, however, the great truth discovered 
by Sir Ronald Ross has been an unfailing guide. But for 
that discovery no progress would have been possible ; . we 
would have been absolutely baffled and utterly lost ; because 
of it, tens of thousands are alive to-day in Malaya who would 
have been dead, while the suffering from which the children 
have been saved is almost beyond belief. 

From the mass of material available, it has been necessary 
to make some selection. Examples of the control of malaria 
in mangrove swamps, on plains, and on hills have been given, 
with plans and illustrations. It is hoped these will assist 
medical officers to control malaria under most conditions, and 
to suggest means of overcoming difficulties, even if a replica 
of the place and problem is not to be found in these pages. 
And I would forcibly impress on the beginner not to be 
daunted by apparent failure. The destruction of anopheles 
always bears fruit, although, as this book shows, the full 
benefits may not be reaped for months or years. 



AUTHOR'S PREFACE TO THE SECOND EDITION xv 

Some readers may be interested in the development of 
our present ideas of malaria. For them portions of the 
previous edition have been retained and marked thus (1909). 
Although the record is of unbroken progress, scientific and 
practical, there are problems ahead. Yet in looking into the 
future, I can see — not far distant — the extension of the present 
methods, the evolution of new ones, and triumphs in averting 
death, in promoting happiness, prosperity and joy, more 
brilliant than any hitherto recorded in the history of medicine 
in the tropics. 

I wish to acknowledge my indebtedness to Mr C. 
Ward-Jackson for valued assistance, and for revising and 
correcting the proof sheets. 

Malcolm Watson. 



Klang, 

Federated Malay States, 

z^rd July 1921. 



CONTENTS 

CHAPTER I 
INTRODUCTION 

British Administration in the Federated Malay States — Position 
and Climate — A Short History of Malaria to 1900 



CHAPTER II 

TOWN OF KLANG FROM 1900 TO 1909 

In 1901 — Choice of Anti-malarial Method — A Fortunate Choice — A 
Stroke of Luck — Preliminary Steps — Anopheline Breeding- 
places — Proposals made to Government for Drainage Scheme 
— The Outbreak of 1901 — Work done in Klang — Cost — Our 
Mistakes — Results ....... 



CHAPTER III 

PORT SWETTENHAM FROM 1900 TO 1909 

Port Swettenham in 1901 — Opening of the Port — The Outbreak — 

Work Done — Cost of the Works at Port Swettenham . . 21 

CHAPTER IV 

RESULTS OF DRAINAGE OF KLANG TOWN AND 
PORT SWETTENHAM, 1901 to 1909 

Malaria treated at Klang Hospital — Reduction in Number of 
Deaths Registered — Children Infected with Malaria, Klang — 
Children at Port Swettenham . . . . .25 

ivii B 



xvhi CONTENTS 

CHAPTER V 
THE STORY OF A COAST ROAD 



PAGE 



A Wave of Malaria— Malaria in the District of Kuala Selangor— 
Obstructed Drainage— Proposals for an Irrigation Scheme— 
The Wave Recedes ....•■■ 34 



CHAPTER VI 

KAPAR DRAINAGE SCHEME 

A Report on Road Drainage — The Scheme Approved . . 39 

CHAPTER VII 

A MALARIAL SURVEY 

Ceylon Planters — Coffee Planting — Its Failure — The Beginnings 
of the Rubber Industry — The Kapar Drainage Scheme : an 
Experiment — Latent Malaria — The Malarial Survey . . 42 

CHAPTER VIII 

THE MALARIA OF THE COASTAL PLAIN AND 
ANOPHELES UM BROS US 

Different Zones of Land — The Coastal Plain — The Mosquito of 
the Virgin Jungle — Anopheles umbrosus — Its Relationship to 
Jungle — A Working Rule — Details of Estates — Disappearance 
of Malaria from certain Rural Areas — Summary of Examination 
of Children on Flat Land Estates ..... 46 

CHAPTER IX 

THE MALARIA OF MANGROVE SWAMPS AND 
ANOPHELES LUDLOW I 

The Philippine Islands — Anopheles rossi — A. indejinita — A. ludlowi 
— Dr De Vogel's Work— Malaria in the Andamans — A 
Mangrove Swamp — Two Zones — Malaria due to A. ludlowi — 
The Control of A. ludlowi — Carey Island . . . • 77 



CONTENTS xix 

CHAPTER X 
THE COASTAL HILLS 



PAGE 



The Persistence of Malaria in Certain Rural Areas — Anopheles 
maculahis in Ravine Streams — Not 'in all Ravines : not always 
Present — Examples of Persistence of Malaria— What is a Hill? 86 



CHAPTER XI 

THE EFFECTS OF MALARIA 

Effect of Malaria on Europeans — Effect of Malaria on Coolies — 
Variation of Death Rate with Spleen Rate — The Death 
Rate uninfluenced by Quinine — Public Works — Estates — India 
— Wastage of a Labour Force — Economic Effects of Malaria 
on the Estate ....... 93 

CHAPTER XII 

ON QUININE 

Value of Quinine Administration — Our Hopes — A Total Failure — 
The Limitation of Quinine — Observations on Quinine Adminis- 
tration — Time and Form — Relation of Dose to Intensity of 
Malaria — Ill-effects of Quinine — Cost of Quinine Administra- 
tion — Relative Values of Quinine Administration and Drainage 
— The Experience of the War — Sir Ronald Ross on Quinine . 106 



CHAPTER XIII 

SEAFIELD ESTATE AND SUBSOIL DRAINAGE 

A Grave Problem — The Area to be Drained — The Engineering 
Problem — The Scheme Approved by the Directors — 
A. maculatus as a Carrier of Malaria — Progress of the Work 
on Old Seafield : on New Seafield ..... 130 

CHAPTER XIV 

SEAFIELD ESTATE (continued) 

The Medical Results from the Drainage — Death Rates — Lives 

Saved — Spleen Rates and the Children .... 140 



xx CONTENTS 

CHAPTER XV 
SEAFIELD ESTATE {continued) 

PAOK 

The Financial Results of the Drainage — Indian Labour— The 
System of Recruiting — No Indentured Labour — Not an 
Asset on an Unhealthy Estate — Chinese Labour— The Different 
Dialects— Difficulty of Working — Chinese Labour on Unhealthy 
Estates — High Wages — Chinese Societies and Guilds — 
Advantages and Disadvantages of Indian Labour — Average 
Cost of Production of Rubber by Indians and Chinese — 
Estimated Gain to Seafield Estate in 1919 . . 147 

CHAPTER XVI 

ON THE BORDER OF THE HILL LAND 

North Hummock Estate — The Value of Subsoil Drainage to Agri- 
culture—A Letter from the Manager— Bukit Rajah Estate — 
Batu Blah Drainage — Midlands Estate — Damansara Estate — 
Jugra Hill — Karimon Island . . . . 157 

CHAPTER XVII 

OILING 

Oiling in 1901 — Useless in Swampy Jungle — Oil in Panama — Sungei 
Way Estate — Success against A. maculatus — Improved Health 
— How Oil acts — Some Practical Points — A Comparison of 
Subsoil Drainage and Oiling ..... 186 

CHAPTER XVIII 

SOME OTHER EXAMPLES OF HILL CAMPAIGNS 

Failures and Successes — Glenmarie — The Selection of Sites — 

Examples ........ 194 

CHAPTER XIX 

ON THE POSSIBILITY OF ALTERING THE COMPOSITION 
OF WATER AND THE ANOPHELINES BREEDING IN IT 

Krian Irrigation Padi Fields— Health of the Children in Krian— The 
Anophelines of Krian Irrigation— Bukit Gantang Valley Rice 
Fields— The Health of the Children— The Anophelines of Bukit 
Gantang Valley — Table comparing the Anophelines at Bukit 
Gantang Valley and at Krian — Conclusions from the Observa- 
tions of the Krian and Bukit Gantang Irrigation Padi Fields — 
The Effect of Drainage on Different Species of Anophelines . 20[ 



CONTENTS xxi 

CHAPTER XX 

THE INLAND HILLS 

PAGE 

The Need for Research— The Happy Valley— Dr Strickland- 
Observations in Kuala Lipis and the Pahang Railway Con- 
struction — Tembeling Estate— Observations on the Railway 
Construction at Batu Arang in Selangor — Observations in the 
State of Pahang from the Gap to Ginting Simpah via Tras and 
Bentong — Dr Strickland's Discovery .... 217 

CHAPTER XXI 

THE MALARIA OF RIVERS 

Tidal Rivers — Brackish — Non-brackish Rivers with Swampy Banks 
in the umbrosus Zone— Estates "SA", "HW", and "JS" Coolie 
Lines removed — Results — Rivers still farther Inland — The Batu 
Road Swamp — The Mimosa Line — Inland Plains — The Smaller 
Rivers — Tarenteng Estate — The Mosquitoes of Stream Courses 
by Dr Strickland ....... 223 

CHAPTER XXII 

THE REAPPEARANCE OF MALARIA 

I. Port Swettenham in 1906 — Criticism of the Original Drainage 
Scheme — Port Swettenham from 190910 1920 — Extension of the 
Drainage — A Low Level Scheme — II. The Reappearance of 
Malaria on an Estate within Tidal Influence — The Cause of the 
Outbreak — The Remedy — III. The Story of a Coast Railway — 
Malaria re-appears on " P.G." Estate — The Cause of the Out- 
break — Borrowpits and Obstructed Drainage — A. ludlowi — The 
Remedy — Improved Health — Death Rates — Spleen Rates — 
Estate "A" — History repeating Itself — The Romans in the Fens 
of Lincolnshire — IV. Malaria from the Delayed Spread of A. 
maculatus — Klang Town — Batu Unjor Estate — Haron Estate — 
Estate "S" — V. The Re-appearance of Malaria on a Hilly Estate 
— A. maculatus — The Cause — The Remedy — The Result . 233 

CHAPTER XXIII 

SCREENING 

Experiments with a Hospital at Jeram — An Estate Experiment — Its 

Failure — Screened Houses — Screened Hospitals . . . 257 



xx ii CONTENTS 

CHAPTER XXIV 

ON DRAINAGE 

PAGE 

Co-operation between Medical Officer and Engineer— The Com- 
position of Soil— Water in Soil— Surface Tension— The Water 
Table— How a Drain acts— The Results of Drainage— Subsoil 
Drains— Different Forms— Poles and Faggots— Stone Drains— 
The Pipe Drain— The Cylindrical Pipe Drain— How Water 
enters the Pipes— The Drainage of Ravines— A Demonstration 
at Klang— Dangerous Swamps drained by Earth Drains— The 
Grading of Brick Drains— Filling up a Swamp— Mosquito-borne 
Diseases other than Malaria — Summary .... 264 

CHAPTER XXV 

ON MOSQUITOES 

Difficulty of Classification— Dr Strickland's Researches— The Rossi 
Group — A. ludlowi— The umbrosus Group— The Mosquitoes of 
Virgin Jungle ; on Hill Land ; on Flat Land — The Peat Belts — 
The Mosquitoes of Stream Courses— On the Mosquitoes of 
Ravines — A. umbrosus — A. montanus — A. aitkeni — When a 
Ravine is opened — Resulting Conditions — Five'Examples — The 
Silent War ........ 282 

CHAPTER XXVI 

THE MALARIA OF KUALA LUMPUR 

Measures taken to bring about its Abatement, showing the Failure 
of Empiricism and the Success of a Scheme based on the Findings of 
Entomological research. By Dr A. R. Wellington, M.R.C.S., 
L.R.C.P., D.P.H., D.T.M. and H., Cantab., Senior Health Officer, 
F.M.S. 

Introduction — Situation — Distribution of Malaria previous to 1906 
— Outbreak of Malaria in the Hill Land — The Malaria Com- 
mittee, its Investigations, Discoveries, and Recommendations 
— First Attempt by Public Works Department to exterminate 
Malaria by Drainage — Investigations by Health Officer and his 
Findings — Experimental Drainage on Petaling Hill — Second 
Attempt by P.W.D. — Continuance of Malaria — Confirmation of 
maculatus as a Carrier — Formation of Malaria Advisory Board 
— Work commenced by Malaria Advisory Board — European 
Residential Area cleared of Malaria — Influence of Drainage not 
confined to Residential Area — Death Rate — Pratt and Fletcher's 
Theory confirmed by Strickland— Danger of clearing Valleys — 
Work Done — Conclusions ...... 293 



CONTENTS xxiii 

CHAPTER XXVII 
ANTI-MALARIAL WORK IN SINGAPORE 

PAGE 

By P. S. Hunter, M.A., M.B., D.P.H., Deputy Health Officer, 
Singapore. 

A Malarial Survey — The Telok Blangah Area— The Results of 
Drainage on the Spleen Rate — Anopheles maculatus in Ravines 
— Dry Weather most Suitable for It — Subsoil Pipes Best — 
Chinese Squatters — Too many Open Drains a Danger — A 
Drained Swamp may be more Dangerous than when Undrained 
— Concrete Channels — A. ludlowi in Enormous Numbers — Cost 
of Work borne by Municipality — The Island of Blakan Mati — 
Malaria in the Garrison — Subsoil Drainage — Summary . .321 

CHAPTER XXVI II 

ON STATISTICS 

Hospital Statistics — Admissions — Outpatients — A Fallacy — Deaths 
— Spleen Rates — Immunity in Malaria — Observations by 
Sydenham in 1661 to 1664 — Cinchona no Certain Cure — The 
Best Method of Administration — On Prognosis — The Seasonal 
Variation of Malaria — The umbrosus Wave — The maculatus 
Wave. ...... . 337 

CHAPTER XXIX 

RESULTS 

Towns of Klang and Port Swettenham — Estates under the Author's 
Care — Fall in Death Rates — Lives Saved— The Estate Labour 
Force of the F.M.S. — Improved Health — Lowered Death Rate — 
Lives Saved — Singapore — The Lowered Death Rate — The 
maculatus Wave — Estimated Number of Lives saved in 
Singapore — Estimated Number of Lives saved in the Malay 
Peninsula — Panama ....... 350 

CHAPTER XXX 
CONCLUSIONS 

Mosquito Reduction — Rice Fields — Quinine — Screening — The 

Labour Problem ... . . 361 

References .... ... 367 

Appendix — Singapore Death Rates ..... 370 

INDEX 373 



LIST OF ILLUSTRATIONS 



Spleen 



i. The Silent War ..... 

2. Virgin Jungle in Malaya . 

3. Map of Town of Klang in 1901 

4. Small Hills of town of Klang 

5. Hill-foot Drain, town of Klang . 

6. A Main Drain at Klang .... 

7. Flooding of Port Swettenham in 1909 

8. Tidal Valve in South Bund at Port Swettenham 
9 Drainage Plan of Port Swettenham 

10. Chart of Admissions for Malaria, Klang 

11. Chart of Deaths in Klang and Port Swettenham 

12. Kapar Drainage Scheme 

13. Sites for Coolie Lines .... 

14. Plan of Estate "C" 

15. Map of Parts of Districts of Klang and Kuala Selangor. 

showing Spleen Rates in 1909 

16. Map of a Part of Kuala Langat District, showing 

Rates in 1909 ..... 

17. South Bund at Port Swettenham, showing anopheles 

breeding-places in mangrove 

18. Breeding-places of Anopheles ludlowi . 

19. Breeding-places of A. ludlowi .... 

20. Drains in which A. ludlowi does not breed 

21. A Sluice Gate on a Tidal River .... 

22. An Automatic Vertical Tidal Gate on Carey Island 

23. Shows the Great Depth of Drainage on Carey Island . 

24. A Bund on Carey Island. .... 

25. An Automatic Flap Tide Valve on Carey Island 

26. General View of Hill Land Estate 

27. Stream in Hill Land ..... 

28. Chart showing Variation of Death Rates and Spleen Rates 

29. Chart showing Wastage Rates and Spleen Rates 

30. Young Rubber invaded by Jungle 

31. Plan of Ravines of Seafield Estate — Southern Division 

32. Seafield Estate. The Original Condition of Ravine " 

before Subsoil Drainage .... 

33. Seafield Estate. The Ravine of Fig. 32 when first piped 

34. Seafield Estate. The Ravine of Fig. 32 when finished 



Frontispiece 
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XXVI 



LIST OF ILLUSTRATIONS 



35. An Open Cement Channel in Kuala Lumpur . 

36. Subsoil Drainage. Finishing the Day's Work 

37. Subsoil Drainage. A Wash-out 

38. Subsoil Drainage. A Blocked Drain . 

39. Seafield Estate. Ravine "A" in a Tropical Shower . 
40 Plan of Ravines of Seafield Estate — Northern Division 

41. Seafield Estate. Lower End of Ravine "A" . 

42. Seafield Estate. End of Subsoil Pipes in Ravine ''A" 

43. Seafield Estate. Mothers and Children on Old Seafield 

44. Chart of the Death Rate of Seafield Estate 

45. Plan of North Hummock Estate 

46. Plan of Bukit Rajah Estate 

47. Plan of Midlands Estate 

48. Chart of Malaria Admissions of Midlands Estate 

49. Chart of Death Rates of Damansara Estate 

50. Jugra Town — Abandoned Houses 

51. Malarco ...... 

52. Malarco — Subsoil Drain 

53. Subsoil Channel at Malarco 

54. A Buried Stream at Malarco 

55. Meyer's Oil Sprayer 

56. A Well-oiled Ravine 

57. Plan of Estate "Glenmarie" 

58- „ "DJ" . 

59- „ "JM" . 

60. „ "JC" 

61. Photo of Estate "SC" .... 

62. „ " SC" . 

63. Plan of Estate " SC " . 

64. Krian Irrigation — A Main Channel 

65. „ Flooded Land . 

66. „ Map .... 

67. Bukit Gantang Valley 

68. „ Map of 

69. Rice Field near Malacca — Not Cultivated 

70. „ Cultivated . 

71. The River at Kuala Lipis 

72. Coolie Lines in Pahang Jungle . 

73. River within Tidal Influence, Brackish . 

74. Plan of Estate "HW" . 

75. A Stream too large for Pipe Drainage . 

76. The Perak River ..... 

77. Port Swettenham — A Blocked Drain 
7S. „ Another Blocked Drain 

79. Culvert 87 at Port Swettenham . 

80. Section through New Sluice Gate at Port Swettenham 

81. Wicken Fen .... 

82. Wingland Marsh .... 



PACK 

face 136 

.. '38 



LIST OF ILLUSTRATIONS 



xxvu 



83. Plan of Extension of Drainage of Klang Town 

84. Haron Estate. Chart of Maculatus Wave in 1919 . 

85. Mosquito-proof Coolie Lines .... 

86. Plans of a Screened Hospital (a), (6), (c) 

87. Diagram showing the Direction of Pressure and Lines of 

Movement of Water in Drained Land 

88. Diagram of Influence of Distance between Drains on Depth 

of Drainage. (After King) .... 
89 to 93. The Evolution of the Drain Pipe 

94. Vegetation in a Ravine destroyed by Silt 

95. Silt Pits .... 

96. The Drain is almost Obliterated 

97. A Sendayang Swamp ..... 

98. Jugra Town — Invasion by Jungle 

99. The Ravine before Drainage .... 
ico. Original Central Drain and Rubble Herring-bone Lateral 

Drain ....... 

101. Central Concrete Half-channels covered by Perforated 

Concrete Slabs ..... 

102. Petaling Hill Subsoil Pipes .... 

103. Ravine with Central Concrete andiRubble Drains 

104. Club Valley Road, Original Condition 

105. Club Valley Road ..... 

106. Concrete Open Channel and Shallow Contour Drain 

107. Map of Kuala Lumpur ..... 

108. Open Ditch in Singapore 

109. Concrete Ditch in Singapore .... 

1 10. Septic Tank in Singapore .... 
ill. Chart of New Seafield Estate, showing the constantly sick 

in 1913 and 1914 ... 

1 12. Chart showing the Admissions for Malaria to Klang Hospital 

The umbrosus Wave ..... 

113. The Curve of Malaria from A. maculatus 

114. Chart of Death Rates of Labour Force under the Author': 

Care ....... 

1 1 5. Chart of the Death Rates of the City of Singapore . 



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352 
358 



" Life is a warfare and a stranger's sojourn." 

M. Aurelius Antoninus. 



THE PREVENTION OF MALARIA IN 
THE FEDERATED MALAY STATES 



CHAPTER I 

INTRODUCTION 

British Administration in the Federated Malay States. — -Only 
a generation ago a small band of Britons was sent to Malaya. 
Utterly insignificant in number, backed by no armed force 
to give weight to their words, they had strict orders only to 
advise the native chiefs, and not to rule. Civil war raged in 
the land. To take one step from the beaten track was to be 
lost in a forest, which had held men in check from the beginning 
of time. They were expected to create order from jungle, and 
turn strife to peace. 

A hopeless task it might appear ; but they brought with 
them those qualities which have spread the power and influence 
of Britain throughout the world. In the work of these men will 
be found the highest examples of the tact, of the scrupulous 
dealing with the native rulers, and of the sound administration 
which have built up the British Empire ; and the progress they 
made is almost too great to grasp. They found it a land deep 
in the gloom of an evergreen forest whose darkness covered 
even darker deeds; for man fought with man, and almost every 
man's hand was against his fellow's. During the course of 
a generation, thousands of acres were wrested from jungle ; 
thousands of people now live in peace and plenty ; a railway 
stretches from end to end of the lands ; roads, second to none, 
bear motors of every kind ; while chiefs, who had never entered 
each other's country except with sword in hand, met in harmony 
in conference with the man whose genius had made Federation 
possible. 



2 INTRODUCTION 

In Svvettenham's History of British Malaya will be found 
the record of this marvellous change ; and, with scientific 
instinct, the author contrasts the condition of the Federated 
States under British control with that of the other Malay 
States which were still under Siam and their native rulers. 
These form a "control" to the British experiment. To the 
Federated Malay States, British administration has brought 
wealth and prosperity to a degree to which can be found no 
parallel. 

And with wealth has come health. From hundreds of 
square miles malaria, which formerly exacted a heavy toll from 
Malay and foreigner alike, has been driven out. 

Day by day it is being pushed back. Strong as its position 
now is in the hills, that too is being undermined, and it is my 
object to record the victories of the past and indicate the line 
of attack for the future. 

Position and Climate. — The following observations have been 
made in portions of the Malay Peninsula lying between the 2nd 
and 6th degrees of North Latitude. The Peninsula itself lies 
between the iooth and 107th degrees of East Longitude. The 
climate is, therefore, to be described as equatorial ; that is, it 
is equable, hot, moist, and without extremes either of heat or 
cold. Than such a climate none could be conceived more suit- 
able for the propagation of the mosquito, and both in number 
of species and number of individuals, the Culicidse are well 
represented. 

The rainfall is large, and is, on the whole, fairly evenly 
distributed throughout the year. In those parts of the 
States where a difference is noticeable, the wettest period is 
from September to March. The rainfall is always consider- 
ably heavier in localities near hills than on flat land near 
the coast. 

The average rainfall in the hilly inland districts varies 
between 100 and 200 inches, while in the drier parts of the 
States it is usually recorded at from 70 to 100 inches per 
annum. 

The general meteorological condition is as represented by 
the official return given in the medical report of Selangor for 
the year 190S. 1 There are differences from year to year and 
between different places in the Peninsula, but these will be 
referred to later where necessary. 




Fig. 2. — Virgin Jungle in Malaya. 



[ To f nee page 2. 



POSITION AND CLIMATE 



Meteorological Retu 


rn of Kuala Lum]. 


ur / 


or the 


yeat 


1908 






Temperature. 


Rainfall. 


Winds. 


a 
" a 


a. 
■go 


a 

T3 B 
£"8 


Is 


bo 


OS 

a 


43 m 

§■3 

II 


& a 


cS S 
° 

°5 


£ 


January 


147-2 


53-i 


9°-5 


71-1 


19-4 


80-9 


7.71 


79 


N.-W. 




February 


149-6 


52-5 


go- 1 


70.6 


19-5 


8o-8 


14-01 


77 


Calm 




March . 


143-9 


52-6 


89-8 


70-8 


ig-o 


8o-2 


IO-IO 


79 


S.-W. 




April . 


144.2 


52-3 


91-2 


73-1 


I8-I 


8I-I 


7-25 


75 




T3 


May 


H7-7 


51-9 


90-5 


72-1 


18-4 


8o-8 


6-42 


78 




-O 


June 


146-4 


52-4 


90-4 


71-9 


18.4 


80 -9 


6-76 


78 




O 


July . 


146-4 


52-6 


89.6 


71-2 


18-4 


80.5 


3-28 


80 






August . 


147-8 


51-6 


89-7 


71-4 


18-3 


80-2 


2-98 


79 






September 


142-8 


52-8 


88-3 


72-0 


16-3 


79-3 


10-17 


81 




2 


October 


142.5 


52-9 


88-7 


72-1 


16-6 


80-2 


8-73 


80 






November 


140-5 


53-2 


88-9 


72-2 


16-7 


79-7 


7-71 


81 


S.-E. 




December 

Mean . 


147-7 


52-8 


89-6 


72-2 


17-4 


80-2 


4-17 


78 


Calm 




H5-5 


52-5 


89-7 


71-7 


1 8-o 


80-4 


7-44 


78 


S.-W. 





Total rainfall, 89-29 inches. 



Under such conditions it is not surprising that malaria 
should, in certain places, be a veritable scourge ; and it has 
been and is so. 

The former residence of the British Resident of the State 
of Perak, built on one of the finest sites in the capital, had to be 
abandoned on account of malaria ; and when recently I visited 
it the fine drive up the hill was so overgrown that I was unable 
to force my way to the top. Proposals for the abandonment 
of the town of Jugra at one time were made. 

Orders were actually given by telegraph by the High 
Commissioner to close Port Swettenham, within two months of 
its being opened, on account of the disease. A coffee estate 
was abandoned a few years ago on account of the impossibility 
of living on it, and at the present moment on many estates this 
disease is the cause of the gravest anxiety. 

Since the disease is essentially a local one, it will be 
preferable if I first deal with my observations of various 
localities, and afterwards treat of their relationship with one 
another. 

Before doing so, however, it will be worth while glancing back 
for a moment at a brief history of our knowledge of malaria. 
We will then be better able to appreciate the position in 1900. 

c 



4 INTRODUCTION 

A Short History of Malaria."- — A disease which appears 
every day, every other day, or every fourth day, with a 
punctuality rivalling a railway schedule, and one, too, which 
goes through such definite phases as shivering, burning fever, 
sweating, and rapid recovery all within a few hours, is a 
phenomenon not readily to be overlooked. We find it referred 
to by both Greek and Latin writers. Though recognised when 
the attack was a regular quotidian, tertian, or quartan fever, 
it was not until cinchona came into use that the irregular 
forms of malaria were distinguished from other diseases 
accompanied by fever. Cinchona was brought to Europe 
about 1640 by the Countess D'El Cinchona, wife of the Viceroy 
of Peru, who had been cured of fever by the drug in that 
country. Its use soon spread through Europe and other 
continents with benefit to millions of unhappy beings. 

By giving quinine the physician had a fairly certain test 
for a malarial fever. If the fever was checked by the drug it 
was malaria ; if not, the fever was not malaria. This was 
a long step forward, yet it still gave no clue to the cause 
of the disease. Already its association with marshes had 
suggested a miasma, or an effluvium, or bad air, rising from 
the swamps, a theory which has given us two of the names 
for the disease, namely paludism and malaria (the Italian 
mal aria, or bad air). Later, when the disease was found to 
be associated with disturbances of soil, quite apart from 
marshes, the theory of a telluric miasma was invented. 

At an early date drainage was seen to drive out malaria 
from certain areas, and there were even suggestions that the 
mosquito might be the means of infection. 

On 6th November 1880, A. Laveran, when working at 
Constantine in Algeria, discovered malaria parasites in 
human blood. The Italians, notably Golgi, Canalis, Marchia- 
fava, Celli, and Bignami, soon took up this discovery and 
worked out the details of the three human malaria parasites. 
They showed how the quotidian, tertian, and quartan fevers 
were due to different and easily recognisable parasites ; how 
the parasites multiplied in the blood by breaking up into 
spores ; and how the fever paroxysm commences at the time 
when the spores are set free in the blood. Although by 
these discoveries we passed from the hypothesis that malaria 
is due to a miasma to the theory that it is due to a living 



A SHORT HISTORY OF MALARIA 5 

organism, not unnaturally it was many years before the miasma 
hypothesis, which had held the field for centuries against all 
comers, was given up by the public. 

The problem then was how these parasites passed from one 
human being to another ; if they lived outside of man, where 
and in what condition ? Failure attended every effort to 
discover the exit of the germs from the human body ; the 
most exhaustive search for them in swamps and soil was 
fruitless. Manson, who had already traced a blood worm, 
the Filaria nocturna, into the mosquito, then suggested 
that certain forms of the malaria parasite, the motile filaments 
given off by the crescents, were for the purpose of infecting 
the mosquito ; and that, when the infected mosquito died, the 
parasites escaped from its body into water, which when drunk 
by man infected him. 

By a series of brilliant researches the genius of Ross 
dispelled the mystery. The parasites were taken up by certain 
mosquitoes (the anopheles) when they sucked blood from a 
fever patient ; male and female parasites were taken up ; they 
conjugated to form a new parasite in the mosquito's stomach 
wall ; this sub-divided into many new fine threads or young 
parasites, which were injected into man when the mosquito 
took its next meal of blood. This wonderful development 
within the mosquito is completed in about ten days in a 
tropical climate. 

Such a discovery, pregnant with so much good for humanity, 
at once attracted widespread attention in every country where 
malaria existed ; unfortunately there are few countries from 
which it is absent. Commissions were despatched from 
European countries to the tropics ; in a few months the 
discovery was confirmed in every detail. The years which 
have passed have still further confirmed the work completed 
by Ross between 21st August 1897 and August 1898. 

Ross left India, in February 1899, to join the newly-formed 
Liverpool School of Tropical Medicine. A few months later 
he set out for West Africa to continue his studies, particularly 
the prevention of malaria and the habits of mosquitoes. The 
policy he adopted was that of mosquito reduction ; arguing 
that by eliminating the mosquito, where this was practicable, 
and it seemed to be so in towns, the disease would soon 
be stamped out. Koch, who had gone to Java to study 



6 INTRODUCTION 

the problem, advocated the use of quinine, hoping to kill the 
parasites in man, thus preventing mosquitoes from becoming 
infected, and conveying the disease to a new host. The 
Italians also adopted this method on a large scale, combining 
with it, in many places, the screening of houses with wire-gauze 
in order to prevent mosquitoes from biting the inhabitants. 
To bring the subject dramatically home to the public, Manson 
in 1900 carried out two experiments. A mosquito-proof 
house was built in a notoriously malarious spot in the Italian 
Campagna, and occupied by Drs Sambon and Low throughout 
the most malarious months of the year. They worked in the 
fields during the day, but retired within the house before 
sunset. Neither observer contracted malaria. The other 
experiment was to bring anopheles mosquitoes, which had fed 
on fever patients in Rome, to London, and there to make them 
bite two people, who had not previously suffered from malaria. 
Both men — one was Manson's son — developed malaria, and 
parasites were demonstrated in their blood. 

Such was the state of our knowledge when early in January 
1901 I found myself in Klang, in the Federated Malay States. 



CHAPTER II 

TOWN OF KLANG FROM 1900 TO 1909 

In 1901. — This town, the headquarters of the district of the 
same name, is situated on the Klang River, some twelve 
miles from its mouth, and five miles as the crow flies. In 
1901 the census of the population showed there were 3576 
inhabitants, occupying 293 houses. Since then the town has 
greatly increased in density of population as well as in area. 
Within the old town limits of 1901 the number of houses 
has increased from 293 to 468, which would give an estimated 
population of 5745. This, I believe, will be found to be less 
than the actual increase of the population. In all subsequent 
statistics when comparison is made between the figures of 
different years it is to be understood that these figures refer 
only to the population within the town limits of 1901, and 
not to those of the present town limits. The old town limit 
was practically the Jalan Raya, except where for three-quarters 
of a mile this road ran parallel with the river, and the river 
was the boundary. 

The area of the town was in 1901 approximately 290 acres. 
Of this 22 acres was swamp, 25 acres virgin jungle, 60 acres 
dense secondary growth in many places 30 to 40 feet high. 
The distribution of these undesirable portions will be seen 
from the map. The whole town was permeated with their 
influence, and it is hardly surprising that malaria was a 
scourge. 

Assuming duty early in January 1901, as Government 
Surgeon of the Districts of Klang, Kuala Selangor, and Kuala 
Langat of the State of Selangor, one of the Federated 
Malay States, I found the hospital at Klang full of malaria. 
It appeared to me that my duty consisted in doing more 
than remaining in hospital all day treating patients, since 
to this there could be no end, if steps were not taken to 
7 



TOWN OF KLANG FROM 1900 TO 1909 




CHOICE OF ANTI-MALARIAL METHOD 9 

prevent infection of the population. At that time, Ross's 
brilliant discovery had been fully confirmed by the Italians 
and others. Manson's 3 dramatic proof at Ostia and at London 
left no doubt of what could be done under certain conditions. 
Ross himself had favoured mosquito reduction, and was actively 
engaged in West Africa in putting this method to the test. 
The Italians 4 were rather in favour of mechanical prophylaxis 
by mosquito netting, and by the use of quinine ; and Koch 
had already reported a success in a small community by the 
regular use of this drug. 

At this time nothing was known about the species of 
anophelines, and the valuable reports of the Commissioners 
of the Malaria Committee of the Royal Society bearing on 
the importance of species were not published until the year 
after the work at Klang had been begun. 

Choice of Anti-malarial Method. — At Klang the work of 

eradicating malaria seemed well-nigh hopeless. No hot or 

cold season even temporarily stopped the mosquito pest; and 

every well, ditch, and swamp teemed with larvae. The active 

co-operation of the native community could not be expected ; 

and active resistance, especially from the Chinese, was certain 

if any attempt was made to enforce the use of quinine. Then 

enforcement of mosquito nets was, of course, impossible ; since 

this would have meant constant house visitation at night. 

Compulsory screening of the whole of every house was 

equally impossible for financial reasons ; nor would people 

have remained within mosquito-proof houses in the evening, 

which is so pleasantly cool after the heat of a tropical day. 

Again, with an area so extensive, subsoil water so high 

as to form permanent swamps, and aquatic vegetation so 

dense, the sweeping out or dealing with the individual 

collections of water in any continuous manner was impossible. 

As surgeon of a district fully ioo miles long, I felt that the 

time I could devote to any anti-malarial measures would be 

limited, and I also felt that no other member of the community 

was at all likely to be willing or able to give more time 

than myself to the supervision of measures which would keep 

down mosquitoes only as long as they were constantly 

applied. And to be quite candid, knowing that the burden 

would fall on myself, I did not quite appreciate the idea 

of having constantly to stand in the sun supervising coolies 



10 TOWN OF KLANG FROM 1900 TO 1909 

and insisting on the thoroughness on which alone success would 
depend. 

Considering all these elements of the problem, I rejected 
as impossible Koch's quinine method, and the Italian 
mechanical prophylaxis, and decided to recommend Ross's 
method of mosquito reduction. To suit the local conditions, 
I determined that any expenditure should be on works of 
a permanent nature. By draining and filling, there would 
be a large and permanent reduction of the breeding-places 
of mosquitoes ; and presumably malaria would be corre- 
spondingly reduced. 

As time has shown, it was indeed a fortunate choice. It 
has been successful far beyond our expectations. No other 
method would have been of any real value ; nor would any 
of them, or even several of them combined, have given anything 
like the results obtained by this. It is easy to see, too, that 
some of the failures to control malaria in other countries, 
reported in later years, were due to those in charge not 
adopting the radical method ; or, where it was attempted, 
not carrying it out with sufficient energy and on a large enough 
scale. 

It was a fortunate choice from another point of view. 
Although our first efforts were on a small scale in a town, 
its immediate success induced me to consider the possibility 
of extending the method to rural areas; and in these, too, 
the results have been not less successful in many places, 
as this volume will show. Although the details have required 
modification to suit the particular habits of the species of 
anopheles we have encountered, the radical method of 
mosquito reduction has everywhere given results superior 
to any other, even among the small populations to be found 
in plantations and villages. 

Although the success was due to a fortunate choice of 
the method adopted, as it turned out, there was a real stroke 
of luck, not recognised until many years after. It was this : 
Had the hills of Klang been higher, or had Klang been 
situated in the main range of hills, instead of being practically 
an island in the coastal plains, the clearing away of jungle from 
the hills and the draining of the valleys and swamps would 
have led to the introduction of a new malaria - carrying 
anopheles, certainly not less terrible than the one we got 



CHOICE OF ANTI-MALARIAL METHOD 11 

rid of by our drainage. Instead of success there would 
have been complete failure; and there can be little doubt 
anti-malarial work would have been set back for years in the 
Federated Malay States. Indeed we escaped very narrowly 
from this peril. For at the very moment my scheme for 
the drainage of Klang reached Government, a proposal 
to test Ross's new theory was received from the then State 
Surgeon of Negri Sembilan. He suggested that if he were 
given the requisite staff, he would make full inquiries into 
the incidence of malaria in the town of Seremban and the 
mosquitoes there. After the records were complete, an 
attempt would be made to eradicate the mosquitoes, and 
the results recorded. Now Seremban is a town among the 
hills of the main range ; so there is every reason to believe 
from my own experiences in similar places the experiment 
would have been a complete failure. Fortunately my scheme 
was sent in with full details of the incidence of malaria in 
Klang, of the houses infected, of the mosquito breeding-places, 
and of the urgent need for action. The case for carrying 
out an experiment in Klang was overwhelming. It won 
the day ; and much more than that, as the years were to 
show. 

Finally I must confess that I by no means expected the 
success, which as a fact followed the works. I had the feeling 
that perhaps a 20 per cent, or 30 per cent, reduction might be 
obtained in the hospital returns. At times a feeling of despair 
came over me. Although I can afford to laugh at it now, 
one portion of the railway line between Klang and Port 
Swettenham always recalls to my mind the feeling of despair 
which came over me there one day, at the height of the 
outbreak of 1901. How was it possible to eradicate a disease 
like malaria, when those infected were liable to relapses for 
years, and at each relapse be capable of infecting others if any 
anopheles at all were present? Then there was the danger of 
infected people coming from other parts keeping up a constant 
supply of malaria. Indeed I was prepared for a total failure of 
the works, and had my answer already prepared should I be 
called to account by Government. It was that Ross had 
proved anophelines did carry malaria ; that to remain doing 
nothing was to remain to die; and that it was at least worth 
spending money to try whether such a scourge could be 



12 TOWN OF KLANG FROM 1900 TO 1909 

removed or even reduced. I record these feelings that they 
may encourage others who may be dissuaded by the apparent 
magnitude of the task from attempting to combat this 
disease. 

Preliminary Steps.— Although the extreme prevalence of 
the disease was apparent to me from seeing so much of it in 
the hospital, some definite statistics were required if Govern- 
ment were to be justified in spending money. And as a 
business transaction it was also necessary to obtain some 
knowledge of the then condition of the town for comparison 
with subsequent periods after the works had been undertaken, 
to determine whether the results were worth the expenditure. 
Unfortunately, although there were many cases of malaria in 
the hospital (they had in fact formed 249 per cent, of the total 
admissions for the previous year) there was no record of the 
residence of the patients beyond the district in which they 
lived. And, although there had been much sickness among 
the Government officers, no record existed of the disease from 
which they had suffered, although numerous prescriptions for 
quinine probably supplied a very significant hint. From the 
death register little help could be obtained since the only 
qualified practitioner in the district was the Government 
surgeon, and only such deaths as were certified by him could be 
advanced as being assigned to their true cause. 

My first care was, therefore, to put the record on a more 
satisfactory footing. The exact residence of every case of 
malaria admitted to hospital was carefully and personally 
inquired into by me. This was very essential, since the patients, 
if casually asked where they lived, generally answered Klang, 
although in fact they might have lived miles beyond the town 
limits. But for these precautions the returns would have exag- 
gerated considerably the actual amount of malaria in the town. 
To widen the basis of the statistics, I had new returns pre- 
pared showing the number of out-patients treated for malaria. 
The disease for which an officer obtained sick leave was 
recorded ; and for some months I personally kept a register of 
the houses within the town which were infected with malaria, 
at the same time recording the number of cases which occurred 
in each as they came to my knowledge. 

These precautions I maintained until I went on leave early 
in 1908. Subsequent changes in the staff led to these being 



ANOPHELINE BREEDING-PLACES 13 

overlooked, and only recently I discovered that it was so. The 
record has again been put on a satisfactory basis ; but 
unfortunately the returns for the years 1908 and 1909 on this 
account are not available for comparison with previous years. 
Fortunately the blood and spleen census of the children is a 
record of the condition of the town not affected by hospital 
statistics. 

Anophdine Breeding-places* — These were found everywhere 
within the town, and a plan was prepared showing their distri- 
bution. In the very centre of the town a swamp existed, with 
houses close up to it. People have told me they shot snipe on 
it from the Rest House. As will be seen from the map the 
town is situated within, upon, and around, a somewhat semi- 
circular group of small hills. At the foot of the hills, especially 
where they bend to form small valleys, the ground water was so 
high as to form permanent swamps. In the absence of a town 
water-supply, wells innumerable were found, mostly teeming 
with anopheline larvae. 

The exact species were not determined for some time after 
the works had been started, but even then some of the original 
swamps had been completely drained. In December 1903 and 
January 1904, Dr G. F. Leicester investigated the anophelines 
of Klang and reported as follows in his Cidicidce of Malaya : ~ — 

" Caught in houses — 

Myzomyia rossii. 
Cellia kochii. 
Myzorhynchus karwari. 

" Caught in jungle — 

Myzorhynchus umbrosus. 
„ sinensis. 

" The larvae of the following mosquitoes were taken : — 

" (a) In mud holes, i.e., small holes made by the feet of a 
heavy animal or a wagon rut in a road — 

Myzomyia rossii. 
Cellia kochii. 

* [1920. — I have left this section as it appeared in the previous edition, 
since it will be more convenient to discuss the anopheles of the F.M.S. in a 
later chapter (see Chapter XXV.).— M. W.] 



14 TOWN OF KLANG FROM 1900 TO 1909 

" (b) In stagnant shallow water supplied by rain and liable 
to dry up — 

Cellia kochii. 

" (c) In swamps — 

Myzorhynch us barbirostris. 

„ sinensis. 

„ umbrosus. 

Cellia kochii. 

" (d) In marshy ground fed by a stream — 

Cellia kochii. 
Nyssorhynchus nivipes. 

" The jungle on the hill range running parallel with the 
Langat Road was entered at several points to ascertain what 
mosquitoes were common there. On the first occasion Myzo- 
rhynchus {Anopheles) barbirostris and Mansonia annulipes were 
obtained in very large numbers during the day, but on the 
hill marked M on the map, no anopheles were obtained in 
the evening though they were abundant in the day. Later 
on the jungle was visited on two other occasions, and the 
number of anopheles present had considerably diminished. 

" There is evidence that great seasonal variation of the 
number of anopheles in the jungle occurs, as on an unknown 
date last year Mr E. V. Carey observed anopheles in great 
numbers in the jungle at the third mile; on a later occasion 
he, with Drs H. E. Durham and Watson, visited this jungle, 
and they were unable to find a single anopheles." 

The disappearance of the mosquitoes does not seem to have 
any relation to the rainfall, nor should I expect this, as the 
swamps at the foot of these hills where larvae were found are 
permanent, and therefore the breeding-places would not dry up 
during the season. 

I think there is a possible mistake with regard to the 
Myzorhynchus which was found by Dr Leicester on the hill. 
My recollection is that he called it at the time umbrosus. In 
his Culicidce he calls it barbirostris. I think the explanation 
is to be found in the existence of another Myzorhynchus so 
closely allied to umbrosus as to be possibly only a variety. It 
differs from M. umbrosus in having two costal spots, the basal 
of which is very small. I think, therefore, that Dr Leicester 
when he came to go over his specimens in Kuala Lumpur 
rejected it as umbrosus on account of the two costal spots, and 



ANOPHELINE BREEDING-PLACES 15 

so called it barbirostris. I call this variety in the meantime 
Myzorhynchus umbrosus x. I am the more disposed to think this 
is the true explanation of the change of name, as Myzorhynchus 
umbrosus x. is the common jungle anopheles, and I have found 
it universally in jungle here. Not only so, but I have found 
it in enormous numbers. On the occasion when Dr Leicester 
visited the hill, the mosquito was in such numbers that simply 
by slipping a test-tube from one part of our clothes to another, 
six or seven mosquitoes could be obtained in perhaps about 
two minutes. Dr Leicester, myself, and an attendant caught 
something like two hundred anophelines in a quarter of an 
hour, and simply could not stand the biting further. I may 
mention that Mansonia annulipes, Desvoidce jugrcensis, and 
Verallina butleri were present in considerably greater numbers 
than the anopheline, so it can be imagined a quarter of an 
hour in that jungle was unpleasant. It is of sufficient interest to 
record, that although Myzorhynchus umbrosus x. was swarming 
in the jungle and attacking during the day, in a rubber estate 
separated only by a 20-feet road, but, of course, free from 
undergrowth, we were entirely free from attack, and no adults 
could be seen. 

The point of the presence of this anopheline is important, 
as I have found it to be a natural malaria carrier. 

Of ten adults taken from coolie lines on Estate " T," one 
was found with numerous zygotes and sporozoites. 

The anophelines found in Klang Town in 1909 have 

been : — 

Pseudo-myzomyia rossii? var. indcfinita. 
Cellia kochii. 
Myzorhynchus barbirostris. 

„ sinensis. 

„ separatus. 

The last of the breeding-places where N. nivipes and N. karwari 
were found was destroyed about 1904, and except for the 
renewal of a small piece of one of the swamps in 1908 through 
a brick drain being put at too high a level, there is now, 1909, 
in Klang no breeding-place suitable for these mosquitoes. It 
is still impossible to say exactly what mosquitoes were carrying 
malaria in 1901, but I think Myzorhynchus umbrosus x. was 
probably the most important one. Only two miles from the 



16 TOWN OF KLANG FROM 1900 TO 1909 

centre of Klang there is now, 1909, a spot in which this 
mosquito abounds, and in which 50 to 100 per cent, of the 
children suffer from enlargement of the spleen, the percentages 
varying universally with the distance they actually live from 
the mosquito's breeding-place. 

In the earth drains and such wells as remain, there has 
been a great reduction in the number of larvse. The number 
of adults which can be caught varies very greatly. In the 
month of August 1909, during a period when the weather was 
dry, not an adult could be caught, although the most careful 
search was made. Yet two months later specimens of the 
above-mentioned species, particularly of M. separatus, were 
caught with great facility, and in fact for about a week rarely 
a night passed without my being attacked as I sat reading. 

Proposals made to Government for Drainage Scheme. — 
Having made definite observations, which convinced me of 
the necessity of striking at the disease, I laid the facts before 
the Klang Sanitary Board in May 1901, with proposals for 
a drainage scheme. The proposals were accepted by the 
Board and were included in the proposed estimates submitted 
to the Government by the Board for 1902. This was entirely 
due to the strong support given to them by the Chairman, 
Mr H. B. Ellerton ; and I wish to record my grateful thanks 
to him not only for his support, but for many valuable 
suggestions in connection with the proposals. When it is 
borne in mind that I personally had no experience of either 
the tropics or of the methods of presenting proposals to the 
Government, those who have had experience of both will 
realise how much Klang owes to Mr Ellerton. 

The support of the State Surgeon of Selangor, Dr E. A. O. 
Travers, was then sought; and in July 1901, I forwarded a 
report to him asking for support for the Board's proposal. 
In it I pointed out that : — 

(a) While the total number of cases treated at the hospital 
during the first half of 1901 showed an increase of 325 per 
cent, over the corresponding period of 1900, the increase 
in the number of malaria cases amounted to no less than 
69 per cent. ; (b) of these malaria cases 55 per cent, came from 
the town, while the estates, which were better drained, sent 
in only 1 1 per cent. ; (c) to my personal knowledge 60 houses 
out of 293 within the town boundary had been infected within 



THE OUTBREAK OF 1901 17 

the previous three and a half months ; (d) the prevailing type 
of parasite was the tropical or malignant form ; (e) a water- 
supply was shortly to be introduced, and it would be unwise 
to bring increased moisture into a town already suffering 
from malaria without previously providing proper drainage ; 
and {/) since in the returns from 1896 onwards 'Malaria 
has been more prevalent in the latter part of the year, the 
marked increase of fever in the first six months of 1901 is a 
matter for serious consideration, and some action in the way 
of drainage is clearly indicated.'" 

This report was accompanied by a plan of the town showing 
the general distribution of the swamps, the breeding-places 
of anopheles, and the houses infected by malaria. The 
proposals received from Dr Travers the strongest support, 
and the Government not only indicated that the proposal would 
be favourably considered, but ultimately doubled the sum asked 
for by the Board. 

The Outbreak of 1901. — It was soon evident that the end 
of the year was to make good our worst fears. The 
outbreak reached terrible proportions. The inhabitants of 
house after house went down before the disease in the months 
of September, October, November, and December, which 
period, incidentally I may mention, coincided with a marked 
rise in the level of the ground water of the town. It is 
difficult to convey any proper conception of such an outbreak 
and the misery it involves ; but the following extracts from 
my note-book will show how much Government officers and 
their families suffered. 

In the clerks' new quarters there were 11 cases with one 
death ; clerks' old quarters, 4 cases ; clerk of works' quarters, 
7 cases ; adjoining quarters, 2 cases ; post office, 2 cases ; 
railway quarters, 16 cases; rest house, 5 cases; inspector 
of police's quarters, 6 cases; police constables, 21 cases; 
in the district officer's quarters the servants were attacked ; 
in the surveyor's quarters all the Europeans were attacked, 
the family consisting of the husband, wife, and two children. 
In my household all my servants were attacked (three in 
number). My wife and I escaped, I believe because the 
servants were sent to hospital at once and were kept there 
until their blood was found to be free from parasites, and 
they were dosed with quinine on their return to work. In 
addition we used citronella oil lavishly on our persons and 



18 TOWN OF KLANG FROM 1900 TO 1909 

clothing in the evenings, and our mosquito curtains were 
thoroughly searched and cleared of anophelines each night. 

In addition to those occupying Government quarters, many 
Government officers were attacked who did not live in 
Government quarters ; and I think two clerks' quarters and the 
dresser's quarters at the hospital were the only ones to escape. 
I may mention these had been attacked in the earlier part 
of the year. 

In the lower lying town, the condition was more terrible. 
Hardly a house escaped. In many cases I found five and 
six persons attacked, and the observations I then made have 
left an indelible impression on my mind. Night after 
night I was called to see the sick in houses and found men 
in all stages of the disease. Many and many a time it 
was only to find the patient in the last stage of collapse 
or in burning fever. The whole population was demoralised ; 
and when in November the death-rate rose to the rate of 
300 per mille, the Chinese suspended business entirely for 
three days, and devoted their energies to elaborate proces- 
sions and other religious rites calculated to drive away the 
evil spirit. 

Work done in Klang. — Although the money voted by 
Government did not become available until 1st January 1902, 
the Board was by no means idle in 1901. All the available 
Sanitary Board Staff was occupied in felling jungle, and 
clearing undergrowth, and doing some minor draining. 
Owners of private land were, under one of the Board's laws, 
compelled to drain and clear their land. The section reads 
as follows and had been in force since 1S90, although its power 
had been little invoked in Klang: — 

" When any private tank or low marshy ground or any 
waste or stagnant water being within any private enclosure 
appears to the Board to be injurious to health or to be 
offensive to the neighbourhood, the Board shall by notice 
in writing require the owner of the said premises to cleanse 
or fill up such tank or marshy ground or to drain off or 
remove such marshy water." (Section 45, Conservancy of 
Towns and Villages Enactment, 1890.) 

This section gave the fullest powers to the Board, and it was 
freely used. 

During 1902 the sums seen below were expended by the 




Fig. 4. — Small Hills of town of Klang. 
The swamps were situated at the foot of the hills, especially where they bend to form cavities. 




Fig. 5.— Hill-Foot Drain, town of Klang. 
Hill-foot Drain, encircling what was formerly a swamp, with water knee-deep in places. 
The drains have rendered this so dry that a part of it is used for the racecourse and part 
for a golf green. No filling was used to obtain this result. On other swamps in Klan°- of 
exactly the same nature much money was spent in " filling," with absolutely no result, as 
the springs from the hills poured water out over the new surface. 

[To face page IS. 



OUR MISTAKES 



19 



Board on draining and filling. The work was not, however 
finished all at once, and even in 1904 some small swamps were 
still in existence. 

It was not until Mr E. V. Carey pointed out that the only 
way of draining the swamps effectively was by contour drains 
at the foot of the hills, the method universally employed by 
planters, that these became really dry. 

The actual expenditure was as follows :— 



Dollars.* 

750 

1925 

8579 

3856 

368 

2340 

I303 

6142 
4000 
2500 
1500 
2554 
* The value of the dollar was fixed at two shillings and four pence of British 

money on 29th January 1906. Before that it fluctuated with, and was of equal 

value to, the Mexican dollar. 



igoi. 

I902. 



1903. 



1904. 



1905. 



Extension of Brick Drains 

Extension of Brick Drains 

Filling in Swamps . 

Main Sewer 

Extension of Existing Drains 

Extension of Brick Drains 

Filling in Swamps . 

Main Sewer 

Rebuilding another Main Sewer 

Extension of Brick Drains 

Lowering of Railway Culverts 

Brick Drains 



This work included the drainage of swamps just outside the 
old town limits, some 16 acres in extent. 

I am indebted to Government for information regarding 
the actual expenditure. This expenditure may appear to be 
very great, but local circumstances are responsible for much 
of it. 

Our Mistakes. — In the first place most of the houses of 
the town were situated close to the river, and connecting them 
with the river were several brick drains, or more correctly, open 
sewers. In order to drain the swamps of the town, which were 
further from the river than the houses, as will be seen from 
the plan, it was necessary to bring the water down these sewers. 
Unfortunately these sewers were at much too high a level to 
allow of this ; and consequently they had to be pulled up 
and rebuilt before the swamps could be effectively drained. 
In some places efforts were made to avoid this, but, in reviewing 
the result, 1 am convinced that had the original drains been 
entirely discarded better results would have been obtained for 
the money spent. The drainage system of the town is bricked 

D 



20 TOWN OF KLANG FROM 1900 TO 1909 

practically only where house sewage flows into it, and nine- 
tenths of the system (1909) is open earth drain. As will be 
seen from the sections relating to rural anti-malarial sanita- 
tion, an open earth drainage system is sufficient in land such 
as Klang. Brick drains (the most expensive part of the works) 
were, as far as a malaria was concerned, unnecessary, and that 
they should properly be debited to ordinary sanitation. 

Much money was spent on filling which could have been 
avoided had the town not been burdened by the legacy of 
its old brick drains.* In some places where no fall could 
be obtained because a brick drain was too high, the land was 
raised by filling. This was very expensive work, and work to 
which I should be strongly opposed now. 

Until Mr Carey pointed out the mistake, much money had 
been spent on filling in at the foot of the hills where our drains 
had proved ineffective. 

I speak plainly of our mistakes, in order that others may 
benefit and avoid similar errors and extravagances. But for 
the necessity of constructing part of the system as a sewage 
system, and but for this unnecessary and expensive filling, there 
is no reason why the works at Klang should have cost more 
than the cost of draining the land, i.e., about £2 an acre ; or 
in other words, about ;£ioo instead of £3000. Thousands of 
acres have been cleared of malaria in the neighbourhood at 
this cost ; and I can see no reason why Klang should not 
have been similarly dealt with at a similar cost. 

Results. — These can be more conveniently dealt with when 
we come to consider the results of the works" at Port 
Swettenham. 

* See Chapter XXIV. 








4 


i 




[To face page 20. 



CHAPTER III 

PORT SWETTENHAM FROM 19OO TO 1909 

The origin of this port was the necessity of having a port for 
the State to which ocean-going steamers could come. It was 
impossible for large steamers to come up the winding Klang 
River in which, at spring tides, a current of 5 or 6 knots runs. 
It was, therefore, decided to make a port at the mouth of the 
river, and work was begun on 1st January 1896. The port 
was to be called Port Swettenham ; it permitted of the entry 
of ocean-going vessels. 

The land at the spot chosen was very low-lying mangrove 
swamp, which was covered at all spring tides to a depth of 
2 or 3 feet by the sea. In the higher tides, especially at the 
September equinox, the tide floods the land for a distance of 
a mile inland. 

The railway was carried along the fore-shore on an embank- 
ment, and wharfs were built connected with the embankment. 
No attempt was made to reclaim the land ; and the workmen, 
during the construction, lived in huts raised on posts above 
the swamps after the Malay fashion. 

Port Swettenham in 1901. — When I assumed duty at Klang 
in January 1901 the wharfs were practically completed, and 
only the finishing touches were being given to the station 
buildings. There were few inhabitants in the place, and there 
were few cases of malaria ; but I observed that new arrivals 
quickly became affected. I also heard there had been a 
considerable amount of malaria among the workmen formerly 
employed there. The place was practically a mangrove swamp 
in which about fifteen acres had been cleared. No attempt had 
been made to reclaim or drain it, and it was full of anopheline 
breeding-places. 

It was obvious what should be done. In February 1901, 
at the suggestion of the Klang Sanitary Board, the resident 



22 PORT SWETTENHAM FROM 1900 TO 1909 

engineer began to clear the land, fill in holes, and generally 
improve the land as far as his votes permitted. There was, 
however, no money available for a proper scheme. 

On the 20th April 1901, at the request of the Acting State 
Surgeon, Dr Lucy, I forwarded a report with recommendations. 
These included, in addition to ordinary sanitary measures : — 

(1) Clearing and levelling the Government Reserve and 

putting it under grass. 

(2) The filling in of abandoned drains. 

(3) A complete scheme of drainage. 

(4) The notification and, if considered necessary, the removal 

to hospital of cases of malaria. 

(5) Experiments with mosquito netting and quinine on 

certain sections of the population. 

In urging these recommendations, I expressed the opinion 
that the "Government Staff shortly to be stationed there will 
be seriously affected and their services much impaired." 

That such was necessary was obvious ; and Government 
put $10,000 on the estimates for 1902. 

Opening of the Port. — On 15th September 1901 the port 
was opened ; and the Government population and the coolies 
connected with the shipping were transferred from Klang to 
Port Swettenham. 

Fearing an outbreak of malaria, and desiring to have a 
record if such occurred, I had a register started of the Govern- 
ment population, showing for each person, name, age, previous 
history of malaria, date of arrival at Port Swettenham, date 
of attack, date seen, nature of parasite, if sent to hospital or 
not, date of return to duty, remarks. Each house had a 
separate page. This was completed within a few days of the 
opening of the port by Mr R. W. B. Lazaroo, the Deputy 
Health Officer ; and in order that I might have as complete 
a record as possible, this officer visited each of the Govern- 
ment quarters. This registration was continued for some 
years, and by this means cases were properly treated from the 
beginning and removed, if necessary, to hospital. 

As far as possible all officers were sent to hospital, and 
to remove one of their objections to this, Government allowed 



THE OUTBREAK 



23 



at my request the recovery of travelling expenses on the 
certificate of the Medical Officer. These precautions had the 
happiest results in the saving of lives, as will be shown 
hereafter. 

The Outbreak. — Immediately after the port was opened 
malaria assumed an epidemic character. In less than a month 
the 1 80 leading coolies were so decimated by disease that the 
remnant refused to live any longer at the port, and returned 
to Klang. Two other batches (about seventy each) were 
imported on the 10th and 20th October respectively, and were 
lodged in separate houses in Klang. Klang, however, was 
then in the throes of the epidemic foreshadowed by the great 
sickness in the early part of the year, and these coolies suffered 
so much that the majority left within a month. The leading 
contractor had then to employ Tamil coolies from a coffee 
estate. The Government population also suffered severely ; 
out of 176 persons, including the crews of the Government 
yachts and launches, no fewer than 118 were attacked between 
10th September and 31st December. 



Table showing the Number of Persons living in Government Quarters 
prior to 31st October 1901, attacked by Malaria within Certain 
Periods after arrival. 



Days after Arrival. 


9-18. 


19-2S. 


29-SS. 


39-48. 


49-58. 


59-68. 


09-78. 


79-SS. 


No. of persons attacked 13 


12 


20 


20 


16 


20 


8 


I 



Two months after the port was opened I visited the native 
houses which had been built; of the 127 inhabitants 78 were 
said to have been attacked, and 25 of the 27 houses were 
infected. 

The effect of the disease on the business of the port was 
very serious. Ships came in and could not unload. Those 
on fixed runs had to overcarry cargo. The crews contracted 
malaria, and after a month or so it was impossible to obtain 
a crew willing to trade to the port. The Harbour and Railway 
Departments were so crippled that they could only imperfectly 
do their duties, and so utterly demoralised did the port become 
that the High Commissioner ordered the closure of the port 
until it could be made more sanitary. To go back to Klang 



24 



PORT SWETTENHAM FROM 1900 TO 1909 



was out of the question, and Government advised the trial of 
the recommendations of a Commission,* which in the meantime 
had been appointed. 

The Commission advised the measures which I had 
recommended in the previous April, and within six weeks the 
work of the port was proceeding without great difficulty. 

An area of about ioo acres was bunded, drained, and freed 
from jungle. All possible mosquito-breeding places were oiled 
freely. Quinine was systematically given to all who would take 
it, and most did. The outbreak had so much diminished by the 
time information about wire gauze was received, that none was 
ever required. 

Cost of the Works at Port Swettenham. 











Dollars. 


1901. 


Jungle clearing, drain 


cutting, forming bunds 


2,000 


1902. 


Filling in, tide flaps 




27,999 


1903. 


Felling and clearing j 
Brick drains 


ungle 




2,563 
1,180 


1904. 


Felling jungle, filling 
Brick drains 


n, etc. 




12,311 
1,541 


1905. 


Clearing scrub, etc. 
Brick drains 
Concrete drains . 


Total 




1,469 
1,022 

2,275 

52,36o 








^^— _H 



* Consisting of the Director of the Institute for Medical Research 
(H. Wright), the State Surgeon (E. A. O. Travers), the District Surgeon, 
Klang (M. Watson), the General Manager for Railways (C. E. Spooner), the 
State Engineer (B. P. M'Glashan), and the Resident Engineer for Railways 
(A. P. Watkins and later D. J. Highet). 




Fig. 7. — Flooding of Port Swettenham in October 1909. 
In October 1909, for the first time since 1901, exceptionally high tides overflowed the 
bunds and flooded the town to a depth of three to four feet. The bunds were about one 
foot above the ordinary spring tides. But for the bunds the town would be flooded every 
fortnight by the spring tides. 



1 1 . , tl _ ,^ 


; MSmm 






, . / 



Fig. 8.— Tidal Valve in South Bund at Port Swettenham. 
The photograph shows the original tide valve which opens outwards only. 

[Tofocc page 24. 



CHAPTER IV 



RESULTS OF DRAINAGE OF KLANG TOWN AND 
PORT SWETTENHAM, I9OI TO 1909 

Two definite experiments were thus carried out on a consider- 
able scale. The experiments were in areas quite different in 
physical characters : the one being a mangrove swamp which 
was reclaimed from the sea by bunds ; and the other on and 
about low hills with swampy ground at the hill foot. Further, 
the two* places were five miles apart. In 1901 they were 
probably the most malarial localities in the district. 

It was not until December 1902 that a water-supply was laid 
on to the towns ; so this factor cannot have influenced the public 
health. That the improvement was not due to any general 
improvement is clearly shown by the continuance of malaria 
in the surrounding district, which thus acts as a control. The 
final proof, an undesirable one, is to be found in the recurrence 
of malaria, after a considerable period of freedom from the 
disease, in one of the places, when its drainage suffered inter- 
ference and its inhabitants spread beyond the drained area ; 
while in other places where the drainage was efficiently upkept 
no such recurrence has taken place. 

Malaria treated at the Klang Hospital. — From 1901 to 1904 
the number of cases treated has greatly diminished. There was 
a subsequent increase owing to the increasing rural population. 





1S94. 


1895. 


1896. 


1897. 


1898. 


1899. 


1900. 


1901. 


1902. 


1903. 


1904. 


Outdoor 
Indoor . 

Total . 

Percentage . 


172 
91 


479 

112 


730 

I 5 8 


554 
128 


694 
163 


668 

251 


737 
467 


965 
807 


364 
4°3 


245 
219 


240 
298 


263 


591 


888 


6S2 


857 


919 


1204 


1772 


767 


464 


538 


20-4 


28-9 


25-0 


19-7 


25-2 


20-2 


24-9 


38-8 


20-4 


I2-I 


II-I 



PORT SWETTENHAM 

Area reclaimed in 1901 within heavy black line 
Remainder reclaimed from 1912 onwards 

Scale of J< Mile 



Outlet A 



B^jfe^'% 




Emery Walker Ltd. sc. 



FlG. 9. — Drainage Plan of Port Swethenham. 



MALARIA TREATED AT THE KLANG HOSPITAL 27 

The table on page 25 shows the number of cases of malaria 
treated at the Klang Hospital, and their percentage to the 
number treated for all diseases. 

The incidence of the disease shown is striking, and the 
following table enables one to appreciate its cause : — 

Table showing the Number of Cases of Malaria admitted to the Klang 
Hospital from Klang Town and Port Swettenham, as compared with 
the Number of Cases admitted from Other Parts of the District. 



Residence. 



Klang ..... 
Klang and Port Swettenham 
Port Swettenham 
Other parts of district . 

Total . 



1901. 


1902. 


1903. 


1904. 


1905. 


33+ 
88* 


I29 


48 


28 


12 


188 


70 


21 


4 


II 


197 


204 


150 


266 


353 


807 


4°3 


219 


298 


376 



* Certain persons 
Year 1901 


lived some Digiit 
1902 


s in Klang and some in Port Swettenham. 

1903 1904 1905 


Cases 
350 






















300 
















4 




4M 






250 














4 




4* 


r 






200 












J 















150 








^ 


^J 

















100 






















50 














































FlG. 10. — Chart showing the Admissions for Malaria to Klang 

Hospital, 1901 to 1905. 

— — ■ From towns. - - - - From other parts. 

Situated as Klang and Port Swettenham are in a malarious 
country, their inhabitants are liable to infection should they 



28 RESULTS OF DRAINAGE OF KLANG TOWN, ETC. 

spend a night away from home in the neighbourhood ; and, 
on the other hand, imported cases of malaria are frequent 
in both towns. A difficulty arises in connection with the 
classification of the residence of new arrivals, who, giving a 
history of malaria shortly before coming to the Town or Port, 
develop symptoms again after they have been in residence 
over eight days, which length of time is generally regarded as 
the minimum incubation period of naturally acquired malaria. 
Such attacks are probably relapses ; yet they might be the 
result of fresh infection acquired after arrival. Consequently, 

1902 1903 1904 1905 



1900 



1901 



Deathi 
350 










De 


iths 


n Kl 


ing and Pt. Swe 


ttenh 


am 




300 










reg 


istere 


cl- 


— as Malaria 


sease 














250 




























200 








k 
























150 








% 
% 
% 
% 




















100 










»\ 


















50 
























1 


































FlG. 11. — Chart of Deaths in Klang and Port Svvettenham, 1900 to 1905, 

so as neither to underestimate the number of cases contracted 
in Klang and Port Swettenham, nor to overestimate the 
benefits derived from the anti-malarial works in the table on 
page 27, a residence of eight days free from symptoms brings 
the case under the heading " Klang and Port Swettenham." In 
the light of these remarks, it is not uninteresting to note that 
of the thirty-two cases recorded from the two towns in 1904, 
eight were probably imported cases having definite histories 
of malaria before arrival, three * were Klang residents, who 

* One was my servant. On 28th October 1904, I found the man in 
charge of the Resthouse at Jugra had malignant malaria, a severe crescent 
infection. Despite a warning my servant slept in the man's room. 
From 6th November to the 9th, he had headache; on the 10th and nth 
his temperatures were 103-8° and 104° F. respectively, and on the 12th 
malignant parasites were'found in his blood. 



REDUCTION IN NUMBER OF DEATHS REGISTERED 29 

nine to twelve days before admission had slept out of the town, 
and eight were rickshaw pullers who frequently sleep away 
from home after a long journey instead of returning to town. 

In 1905 similar deductions have to be made. 

Reduction in Number of Deaths Registered. — The reduction 
in the number of cases of malaria from Klang and Port 
Swettenham was accompanied by a remarkable fall in the 
number of deaths registered in the same places, while there 
was no similar reduction in the number from the surrounding 
district. 

Table A shows the Deaths in Klang and Port Swettenham corrected 
for Deaths occurring in Hospital. 





1900. 


1901. 


1902. 


1908. 


1904. 


1905. 


Fever 

Other diseases . 

Total . 


259 
215 


368 
214 


59 

S5 


46 
69 


48 

74 


45 
68 


474 


582 


144 


"5 


122 


113 



It will be noted that the remarkable improvement in the 
health of the inhabitants occurred in 1902, immediately after 
the anti-malarial works had been undertaken. 

Table B shows the Number of Deaths in Klang District, excluding 
those occurring in Klang Town and Port Swettenham. 





1900. 


1901. 


1902. 


1903. 


1904. 


1905. 


Fever 

Other diseases . 

Total . 


173 
133 


266 
150 


227 
176 


230 
198 


286 
204 


351 
271 


306 


416 


4°3 


428 


490 


622 



The above tables show convincingly that subsequent 
to the anti-malarial works there has been a great reduction 
in the number of deaths, while in the district outside of 
the towns the number of deaths still increases. And it is 
evident, too, from Table A, that the improvement is due 
mainly to the great reduction in the prevalence of malaria. 
Striking as this appears from the tables, the actual reduction 
has been, I believe, still greater, for among the deaths recorded 



30 RESULTS OF DRAINAGE OF KLANG TOWN, ETC. 

as due to "other diseases" many were doubtless due to 
malaria. For in a malarious country the native informant 
is prone to report deaths, really due to malaria, as due to 
diarrhcea, dysentery, convulsions in children, or other terminal 
complications of malaria. Indeed, natives so frequently fail 
to recognise that their illnesses are connected with malaria 
that it has been found necessary to examine microscopically 
for malaria parasites the blood of all cases of diarrhcea, 
dysentery, anaemia, cardiac and renal diseases admitted to 
Klang Hospital, quite irrespective of whether or not the patient 
says he has had fever. That the native informant of death 
should make a mistake can, therefore, easily be understood. 
At the same time, the eradication of malaria to the extent 
that has occurred has undoubtedly improved the health of many 
of the town inhabitants ; so that individuals, who in former 
years would have increased the mortality under " other diseases," 
simply because they were in a low state of health consequent 
on malaria, are now able to resist the attack of such " other 
diseases," or if attacked to overcome them and recover. 

Although a good water-supply was brought into the town 
in December 1902, and greater attention was being paid to 
general sanitation, I could not help believing that the improve- 
ment was due mainly to the diminution of malaria. As all 
deaths, with the exception of those certified by myself (up 
to 1907 the only qualified practitioner within twenty miles of 
Klang), are registered in accordance with the report of the 
friends, I regard the above tables as an " unsolicited testimonial " 
unconsciously given by the native community to the efficacy 
of the anti-malarial works in Klang and Port Swettenham. 

The following table shows how much Government and its 
officers have benefited : — 



Table showing Number of Sick Certificates and Number of Days' 1 
Leave granted on account of Malaria. 





1901. 


1D02. 


1903. 


1904. 


1905. 


Certificates 
Days of Leave . 


236 
1026 


40 
198 


23 

73 


14 
71 


4 
30 



From 1 2th July 1904 until December 1906 no officer in Port 
Swettenham suffered from malaria. 



CHILDREN INFECTED WITH MALARIA, KLANG 31 

The results of the anti-malaria measures also resulted in 
financial loss to me from diminution of my private practice, 
from patients suffering from malaria contracted in Klang or 
Port Swettenham. In 1901 my private practice brought in 
$734 from patients suffering from malaria contracted in Klang 
and Port Swettenham. In 1904 it was nil, and it remained at this 
cipher until 1909 when cases were seen from Port Swettenham. 

Children Infected with Malaria, Klang. — Unfortunately 
in 1901 no examination of the children was made to 
ascertain the percentage affected. I had, however, abundant 
evidence, both in my official and private practice, that they 
suffered severely. The disease frequently ran through a 
household. As an example I may mention that on one 
occasion (15th April 1901), when called to the Astana, the 
official residence of H.H. The Sultan of Selangor, to see a 
child with malaria, I asked if there were any others, and I 
found no fewer than 15 suffering from malaria. 

Since 1904 I have made a series of examinations, at first of 
the blood, and latterly of the spleen and blood of children 
under the age of ten, differentiating according to the age. For 
the sake of simplicity I give only the totals. The examina- 
tions were made in the months of November, December, 
and January, but mainly in November and December. In 
Klang the children were examined both in the centre of the 
town and at its periphery. 

Table showing the Number of Children in Klang Town giving Evidence 
of Malaria on Blood and Spleen Examination. 





1904. 


1905. 


1806. 


1007. 


1909. 


Blood— 












Number examined . 


173 


119 


91 






Number with Malaria 


I 


I 


I 






Per cent, with Malaria 


0-5 


o-8 


IO 






Spleen — 












Number examined . 






142 


71 


455 


Number with Malaria 






I 


3 


13 


Per cent, with Malaria 






07 


42 


2-8 



Convincing as these figures are of the absence of malaria 
in Klang Town, further inquiry showed that cases with evidence 
of malaria had only recently come to the town, and had con- 



32 RESULTS OF DRAINAGE OF KLANG TOWN, ETC. 

tracted the disease previously to coming. For example, in 
1904 the child with malaria belonged to a company of 
travelling players, and had had malaria in Kuala Lumpur ; 
in 1905 the child with malaria was an inhabitant of Klang 
who two months previously had gone to Malacca for a month 
and, when there, contracted malaria; in 1906 the child with 
malaria had arrived only three days previously from Port 
Dickson; and in 1907 the examinations were made not by 
me personally as the others had been, but by a dresser, and 
no history is recorded of those with enlarged spleen. 

In 1909, desiring to have the fullest evidence possible of 
the condition of the town, I personally went to every house in it, 
and also to all the schools, examining in all 463 children* Of 
the 308 examined in the schools five had enlarged spleen, 
giving a percentage of 38 of the school children ; four were not 
residents of Klang, but came in daily ; one from Kampong 
Quantan ; one from 2nd mile Langat Road ; one from Padang 
Jawa (by train) ; one from 2\ mile Kapar Road. 

Thirteen resided in the town ; I give notes of their previous 
history : — Seven were in the police barracks, four of whom 
had been transferred from Sepang, two from Jugra, and one 
had just arrived from Malacca : all gave a history of malaria 
before coming to Klang. Jugra and Sepang are notoriously 
malarious ; two were in Government coolie lines, one having 
previously been in Batu Tiga — a very unhealthy place ; and one 
had come from Kuala Lumpur where it had had malaria ; two 
were children of an old watchman known to me for years who 
told me he had gone to an estate for three months, and when 
there both he and his two children had contracted malaria — 
the estate he referred to has a spleen rate of about 50 per cent. 
One child had come to Klang only ten days previously from 
2\ mile Kapar Road ; the mother informed me the child 
had fever before coming to Klang. One child came from an 
estate 20 miles from Klang known to me to be malarious. 

It is to be remembered that Klang is constantly receiving 
people who are capable of infecting others with malaria if the 
connecting link be present. In Klang Hospital in the years 
1906, 1907, 1908 respectively, 789, 1901, and 1537 cases of 
malaria were treated without any special precautions to prevent 

* The children examined were under an estimated age of ten, in all 
places, unless expressly stated otherwise. 



CHILDREN AT PORT SWETTENHAM 



33 



the spread of infection. One ward had been enclosed by wire 
netting, but when this decayed it was not replaced as there was 
no evidence that malaria was being spread from the 'hospital ; 
for four years I had used mosquito nets in the hospital, but had 
given these up for Tamil patients as they would not use them 
unless compelled to do so; so that in 1907 when the maximum 
number of cases was treated there was the fullest opportunity 
for the infection spreading. No more severe test of the absence 
of malaria-carrying anophelines could be devised. 

That the whole child population of Klang, except that 
known to have contracted malaria outside, should be com- 
pletely free from all symptoms of the disease, is conclusive 
evidence of the value of drainage, and / would add here that 
not one single grain of quinine was given to any of the population 
except to patients actually suffering from malaria in hospital 
and in my official or private practice. 

Children at Port Swettenham. — In 1901 there were thirteen 
children under the age of ten living in Government quarters. 
Of these nine contracted malaria within three and a half months 
of their arrival. 

Table showing the Number of Children with Evidence of Malaria at 
Port Swettenham. 





1904. 


1905. 


1906. 


1907. 


1909. 


Blood examination — 
Number examined . 
Number with parasites 
Per cent, with parasites . 

Spleen examination — 
Number examined . 
Number with enlargement 
Per cent, with enlargement 


187 

1 

1. 14 


76 
O 
O 


IOO 

5 
5 

IOO 
2 

2 


41 

9 

21-9 


109 

9 

8.9 



In 1904 the child who showed infection was found in the 
Police Station, and had only recently been transferred from 
Cheras, where she had fever. In 1906 I found evidence in the 
children of the recrudescence of the disease, simultaneous with 
its reappearance among the adults, as I shall relate. 
For subsequent history see Chapter XXII. 



CHAPTER V 

THE STORY OF A COAST ROAD 

A Wave of Malaria. — Under the District Surgeon of Klang 
are two other districts, namely Kuala Langat and Kuala 
Selangor ; the three are commonly known as the Coast 
Districts of Selangor. At the time I assumed duty, the 
populations of Kuala Langat and Kuala Selangor, like that 
of Klang, were suffering from malaria. In the annual Medical 
Report of the State of Selangor for the year 1899 it is thus 
described : — 

" During the last two years the Coast Districts have been 
visited by severe outbreaks of malarial fever. All nationalities 
have been affected by it, and Government clerks, Tamils and 
Chinese coolies, and Malay settlers have been equally attacked. 
... It is difficult to assign a cause for these outbreaks of 
malarial fever. It was thought at one time that the earth 
work in connection with road-making, granite quarrying and 
spreading, might account for the increase of the fever at Jugra 
in the Kuala Langat District ; but it has been found to be 
equally prevalent on the sea-beach in the Jeram and Kuala 
Selangor Districts, among Chinese fishermen, where no road 
work or quarrying operations had been undertaken." 

Two years later, writing in his annual report for 1901, the 
State Surgeon says : — 

" By far the greatest number of cases of malaria were 
admitted to hospital in the coast districts, which have during 
the last two and a half to three years been attacked with what 
may be called a wave of malaria, principally of a malignant 

type." 

The reader will have gathered from the previous chapters 
some impressions of what this wave of malaria meant to the 
towns of Klang and Port Swettenham, and of the results 
obtained in our attempts to control it. It is now time to 

84 



MALARIA IN DISTRICT OF KUALA SELANGOR 35 

turn to the wave as it affected the district of Kuala Selangor. 
Its study there threw a flood of light on the whole malarial 
problem, broadened the outlook, and had a profound influence 
on the subsequent anti-malarial policy which I adopted. It 
convinced me that controlling malaria over wide rural areas, 
even in low-lying localities with high ground water, and in a 
tropical country with heavy rainfall, was within the range of 
practical politics. 

Malaria in the District of Kuala Selangor. — North of the 
district of Klang, etc., lies that of Kuala Selangor. It stretches 
away towards the N.N.W. for about sixty miles, and is, like 
Klang district, flat for some miles inland from the sea. 

When I assumed duty as District Surgeon of Kuala Selangor 
district in addition to that of Klang, I found malaria was very 
severe. In 1902, being desirous of obtaining as much informa- 
tion as possible about it, I went through the hospital registers 
for the previous years, and obtained the following figures — as 
far as then possible : — 





1896. 


1896. 


1897. 


1898. 


1899. 


1900. 


1901. 


1902. 


1908. 


Total treated .... 


433 


S24 


782 


836 


1837 


2115 


2061 


2297 


1880 


Number with Malaria 


103 


136 


222 


33f> 


1086 


I0O7 


512 


528 


268 


Per cent, with Malaria . 


2.V7 


2 5 -9 


28-3 


40-1 


S9'0 


$O.I 


33-4 


2 3'0 


I4.I 


Number of Deaths in district . 


170 


193 


163 


168 


278 


317 


290 


287 


248 



These figures could be no mere statistical vagary. A definite 
rise in the percentage of the malaria treated at the hospitals 
during a series of years appeared to me to represent the 
existence of some definite fact — a phenomenon, the investigation 
of which was of urgent importance. 

The census had shown an increase of 30-7 per cent, in the 
population of the district, and while the increasing population 
might have accounted for the rise in the malaria wave, it could 
hardly account for the remarkable subsequent fall. I had no 
idea to what to attribute the phenomenon, but I thought some 
explanation might be found in the history of the district. 
Accordingly I read up all the Annual Reports of the District 
Officers, and also those of the State Engineers for the previous 
ten years. The explanation was soon forthcoming. In order to 
open up the country, to which access hitherto had been possible 
only by rivers and creeks, Government had constructed a road 

E 



36 THE STORY OF A COAST ROAD 

and bridle tract for a distance of some sixty miles from Klang 
to Sabak Bernam on the Perak boundary. The road passes 
through the villages and mukims (sub-districts) of Kapar 
(ioth mile), Jeram (20th mile), and Kuala Selangor (28th mile). 
Before the construction of the road the inhabitants had 
opened up the land at certain places, and malaria was not 
present to any serious extent. The road interfered with 
drainage, as there is abundant evidence to show, and it was 
followed by the outbreak of malaria. The road was put through 
in the early years of the nineties, and complaints were soon 
found in the reports of the District Officers, who in no uncertain 
terms accused it of doing serious damage. Mr A. Hale in his 
Annual Report for 1897 says: — 

" Javanese who took up land on the Bukit Rotan road and 
planted it with coffee which was destroyed by flood water, 
the drain having been dammed by the Public Works Depart- 
ment to use as a canal for transport of metal, have now most 
of them planted cocoanuts, as also have many others who 
hold land on the inland side of the coast road, which, as my 
predecessor pointed out, acts like a long dam from Sabak to 
Kapar, as if built purposely to prevent the water getting to 
the sea." 

Stronger evidence could hardly be obtained, but if it was 
required, it was to be found in an Annual Report of the then 
State Engineer. Referring to the Klang end of the Klang- 
Kuala Selangor road, he congratulated the Government on 
the low cost of constructing the road due to the drain on the 
inland side of the road having been used as a canal. There 
is thus evidence that from end to end the road had acted 
as a serious obstruction to drainage of land on its landward 
side, and coincident with this there appeared the remarkable 
increase in the malaria of the district. 

Now about the end of the nineties, we find in the reports 
proposals for a great irrigation scheme for the cultivation of 
rice in the same district. The first step in irrigation is the 
provision of drains to carry off water, so that the amount of 
water on the land may be properly regulated. In 1898 a start 
was made with the Jeram drainage scheme, but before it was 
completed all idea of rice cultivation had been given up by the 
natives in favour of the more remunerative dry cultivation of 
cocoanuts and coffee, made possible by means of drainage. More 



MALARIA IN DISTRICT OF KUALA SELANGOR 37 

and more land came under this cultivation ; the drainage begun 
in 1898 has steadily proceeded ; European cultivation of rubber 
had spread over the district, and with it the district has become 
populated by the Tamil coolie, who is non-immune to malaria. 
Yet the health has improved steadily. Malaria in serious extent 
is to be found only in the hilly land as in the Klang district. 
On the same Bukit Rotan road, where Mr Hale said the 
Javanese coffee was destroyed by flood, a large population is 
now living practically free from malaria. Dr J. Lang Niven, who 
was in charge of the estates there, kindly informed me that of 
seventy-five children whom he examined, only 4 or 6-i per cent, 
had splenic enlargement, and three of the four children had 
been on estates in Southern India before coming to Kuala 
Selangor. 

The parts of this district which are drained are now as 
healthy as any to be found in the country ; while the parts 
still undrained and the hilly land, where A. maculatus is still 
present, are unhealthy. I think, therefore, we may reasonably 
conclude that the rise of the malaria epidemic which coincided 
with the obstruction of the land drainage by the road, and 
the fall in the epidemic which coincided with the more efficient 
drainage of the land, were respectively due to obstruction and 
to drainage. 

(1919). — The preceding was written in 1909. Another ten 
years have served to prove the correctness of the conclusions 
reached in 1903. The following extract published in that year 8 
seems worth reprinting : — 

" This sudden decrease in the amount of malaria, as a 
result of draining comparatively small areas (I was writing 
about Klang and Port Swettenham), is in striking contrast 
to the gradual decrease, the result of the draining of Kuala 
Selangor district. In that district the population is scattered 
along the coast for many miles. The road runs parallel to 
the coast about a mile inland, and when first constructed acted 
according to the official reports of the district officers, as a 
dam preventing the land from being drained." After giving 
the table of malaria treated from 1895 to 1902 inclusive, I 
continue. "In 1898 a start with extensive drainage works 
was made. The first result of the introduction of the labour 
force was further to increase the amount of malaria. The 
work has, however, been steadily pushed on, and the result 
has been a steady fall in the amount of malaria as the 



38 THE STORY OF A COAST ROAD 

drainage works became effective. This, I think, forms an 
interesting contrast to the results obtained in Klang 
and Port Swettenham." 

The next chapter will show how soon the idea of con- 
trolling rural malaria was to bear fruit. 



CHAPTER VI 

KAPAR DRAINAGE SCHEME 

In my first published report of the anti-malarial measures 
of Klang, I referred to the gradual improvement in the health 
of Kuala Selangor district, as the result of draining large 
areas, in contrast with the more rapid improvement, which 
had occurred in Klang and Port Swettenham, as the result of 
measures carried out in a shorter period. These facts came to 
the notice of the late Mr W. W. Bailey, who wrote to Government, 
complaining that the Klang end of the road still obstructed 
the drainage of the land, making it impossible to drain the 
estates efficiently; and attributing the malaria, which then 
existed on the estates, to the road. In support of his pro- 
posals he quoted my investigations in Kuala Selangor, and 
referred the Government to me for further information. 

On 29th April 1904, at the request of Government, I 
forwarded a report which was published, 9 and from which the 
following are extracts : — 

" Roads and other public works, by producing breeding- 
places for mosquitoes, are important agents in spreading 
malaria and filaria. Roads in flat country, especially when 
parallel to the coast, are injurious in two ways: (1) During 
their construction borrow pits are formed, and these remain 
afterwards as mosquito breeding-places ; (2) when completed, 
roads may interfere with drainage of land on the inland side 
of the road." 

I quoted such figures as were available, which showed 
that from 55 to 65 per cent, of the deaths registered among 
residents on the Kapar road were attributed to fever, and 
up to 35 per cent, of the admissions to hospital were from 
malaria — and said, " Without straining these figures, there is 

89 



40 KAPAR DRAINAGE SCHEME 

little doubt that malaria is an important cause of sickness 
and death among the people living along the road." 

Not being a civil engineer I declined to say that the 
drains were insufficient to drain the land, or that the openings 
through the road were insufficient to allow the water to find 
its way to the sea, although in wet weather the whole inland 
side of the road was flooded and the water came to within a 
short distance of the level of the road. I, however, wrote : — 

" It would be going beyond my province to express an 
opinion as to whether or not the Klang-Kuala Selangor road is 
still preventing the drainage of the estates and the land on 
the inland side, but the unanimity of the planters on the 
point and the sight of water standing often many feet higher 
on the landward than seaward side of the road, seem evidence 
sufficient to justify a thorough inquiry. . . . When it can be 
proved that a road interferes with the drainage of the land 
on which any considerable population live (such as on the 
Klang-Kuala Selangor road), then expenditure on drainage 
is advisable from every point of view." I then made some 
remarks on the construction of drains from the point of view 
of anti-malaria sanitation, and the necessity of engineers 
remembering that "work which without excuse leaves a trail 
of malaria behind it is bad engineering. . . ." " Finally, I 
would express the opinion that the stamping-out of malaria, 
or at least reducing it to a negligible quantity, is a much 
more hopeful affair than has hitherto been anticipated. . . . 
The experience of Klang and Port Swettenham, taken with 
the knowledge that malaria has died out of the Fen Country 
in England, while anopheles still flourish in considerable 
numbers, all point in the same direction. I would, therefore, 
urge upon Government that to abolish malaria it is not 
necessary to abolish mosquitoes completely, and that measures 
fntelligently directed at the disease may at once cost little 
and be strikingly effective." 

As a result of the representations made, the Resident- 
General, Sir W. Hood Treacher, K.C.M.G, the acting British 
Resident, Mr Douglas Campbell, the Director of the Institute 
of Medical Research, Dr C. W. Daniels, the Government 
Engineers, Mr W. W. Bailey and other planters, visited the 
Kapar sub-district and held an inquiry into the condition of 
the road and land. The necessity for improved drainage was 
recognised, and a scheme involving the expenditure of $110,000 
was approved. The outlets through the road were enlarged, 




Fig. 12. — Kapar Drainage Scheme. 
One of the main drains, with rubber trees on both sides. 




FIG. 13. 

Photograph showing sites for Coolie Lines selected in the centre of a clearing 

to be at the maximum distance from undrained jungle and hill streams. 

[To Jace page 40. 



KAPAR DRAINAGE SCHEME 41 

necessitating in some places bridges double the length of the 
previous ones ; and the scheme provided 37 miles of main 
drains sufficient for the drainage of 24,000 acres upon which 
the estates now pay drainage assessment. Some of the drains 
constructed are 20 feet wide (Fig. 12, p. 40). The effect of 
this drainage will be shown further on. 



CHAPTER VII 

A MALARIAL SURVEY 

About the time when the Kapar drainage scheme was 
sanctioned, namely in 1904, the pioneers of the rubber 
plantation industry, who had started about 1898 in a small 
way in the coast districts of Selangor, began to obtain 
some tangible reward from their enterprise. Coming from 
Ceylon after the coffee debacle, when that prosperous 
industry had been almost completely wiped out of the island 
within a few months by disease, they had planted Liberian 
coffee in the State of Selangor in the F.M.S. By 1901, how- 
ever, this coffee had ceased to pay. It could not compete with 
Brazilian coffee ; and the price of the local product dropped 
in the course of two or three years from $44 to $12 and 
Si 5 a picul, at which figure it did not pay. Casting round 
for some alternative crop, a few men interplanted their coffee 
with rubber about 1898. From the first the young trees 
throve so well and grew so sturdily that the coffee was soon 
overshadowed and was cut out. By 1904 the new industry was 
firmly established. Planters were confident in its ultimate 
success. Large areas of land for its cultivation were taken 
up, and labour began to come in freely from India. 

If the history of other tropical enterprises was to be 
taken as a guide, the opening up of the land, especially 
when done with imported labour, was likely to produce 
virulent outbreaks of malaria, and to be costly in lives, both 
of Europeans and Asiatics. My hospital returns showed 
how severely the existing estates were suffering already, 
and I determined to study the matter in more detail. 

From one point of view this great agricultural development 
presented a unique opportunity for the study of tropical 
malaria. From small areas like Klang and Port Swettenham, 
malaria had almost been completely eradicated by the 

42 



A MALARIAL SURVEY 43 

draining of swamps, and the clearing of jungle ; and from 
Kuala Selangor malaria, I gathered the idea that the disease 
could be controlled over wider areas. The great agricultural 
development, which was to be assisted by the Kapar drainage 
scheme, was now to put the idea to the test. It was, 
indeed, from my point of view a great experiment in the 
prevention of malaria ; that it was to be on a scale infinitely 
larger than any experiment, which would have been undertaken 
as such, was no disadvantage ; while the fact that it would 
be carried out by planters, on practical and commercial 
lines, added to its fascination. 

Arriving in the middle of the epidemic of malaria in 
the coast districts in 1901, I commenced work at once on 
the control of the disease, but I always felt that I was 
handicapped by the absence of information which would 
have been available had the records of previous years been 
more complete. In the new developments, I was in a much 
more favourable position. I was witnessing the " birth," so to 
speak, of many new estates. The opportunity was afforded 
me of examining and recording the conditions which existed 
on them from their earliest days, and, as it has happened, 
I have since been able to watch their development for many 
years. Further, by 1904 I had acquired a considerable know- 
ledge of what malaria was, and how it affected a community 
— a knowledge which I did not possess in 1901. Between 
1901 and 1903 I had devoted considerable time to microscopic 
work on the blood of patients admitted to hospital, and to 
the clinical aspects of malaria. It soon became evident 
that many patients were really suffering from malaria, who 
when admitted, complained of symptoms other than pyrexia. 
Some of these observations were published in 1905 in a 
paper entitled "Some Clinical Aspects of Quartan Malaria." 10 
In it I showed that in 1818 per cent, of the cases pyrexia 
was absent for periods averaging 6-4 days; and in 18-18 
per cent, of the cases the rise in temperature was at so much 
longer intervals as to lead to little, if any, importance 
being attached to it by the patient. A considerable ex- 
perience of labour convinces me that 1 or 2 per cent, of 
coolies working on malarious estates have pyrexia of which 
they are unconscious ; and which they deny, even when 
the thermometer shows a temperature of 102° F. The same 



44 A MALARIAL SURVEY 

will often be seen in hospital. I was led to the conclusion that 
while there might be much pyrexia and few, if any, parasites 
to be found in the peripheral blood during the first few days 
of the illness, the later stages might show large numbers of 
parasites and no pyrexia, as immunity was becoming 
established. It appeared to me that sufferers from malaria 
might be divided into two classes, those with pyrexia and 
those without, the latter being neither fewer in number 
nor less in importance. And the more I see of malaria 
the more I find to support this conclusion. It supplied an 
explanation of the extraordinary fall in the number of deaths 
registered in Klang in 1902 as due to diseases other than 
malaria ; and the observations on coolies on large doses of 
quinine and apparently in good health referred to on p. 112 
further bears it out. 

It is sometimes said that the native registers everything 
as malarial fever, and that the returns grossly exaggerate the 
amount of the disease. This may be so where there is 
little malaria. I am convinced, however, that where there is 
any considerable amount of malaria the error is entirely the 
other way, and that many deaths from malaria are recorded 
as due to its complications instead of to the disease to which 
they are really due. In confirmation of this view, there 
is the great fall in the number of deaths recorded as due 
to diseases other than malaria when malaria was reduced in 
Klang, as shown in the table on p. 29. 

The result of my microscopic work in hospital con- 
vinced me of the enormous amount of malaria on the estates 
of the district ; and, in 1904, I determined to carry out as 
complete a survey as my official work would permit. 

Choosing the most unhealthy months of the year, November 
and December, I visited a number of estates in different parts 
of the district, and made examinations of the fresh blood of 
the children. The work was laborious, but the specimens were 
taken by an assistant ; and I examined about eight to ten an 
hour. Out of the 298 children under the age of ten examined 
in 1904, no fewer than 101, or 3389 per cent, were infected. 
During the same months, 1905, 1906, and 1907, either blood or 
spleen examinations were made, and in 1909 and the early part 
of January 1910, examinations of the children on every estate 
of Klang and Kuala Langat districts were made either by 



A MALARIAL SURVEY 45 

Dr Macaulay or myself, and blood examinations were also 
made by Dr Macaulay on some estates. The species and 
breeding-places of the anopheline have also been determined. 

These observations have been continued by my medical 
officers and myself year by year until the present date (1919), 
as the subsequent pages will show. It is probably rare for one 
man to have the opportunity of making so long a series of 
observations under the conditions which obtain here. If so, 
they must have an added interest, even if they are not a 
unique record. 



CHAPTER VIII 

THE MALARIA OF THE COASTAL PLAIN AND 
ANOPHELES UMBROSUS 

Perhaps the word " Plain " is not altogether apt. If it conveys 
to the reader the notion of an open treeless plain, something 
akin to a prairie, it certainly has misled him. No such thing 
as a treeless acre of land exists in Malaya. The country is 
naturally and permanently covered with a heavy jungle; only 
where this is felled, burned off, and cleared of all weeds every 
three weeks or less, does open land exist. 

The land to which I allude is the alluvial land between high- 
tide level and the nearest lower or Coastal Hills. In the course 
of our inquiry, it will be found convenient to consider malaria 
as it is found in the different zones of land existing in the 
Peninsula. The zone nearest the sea I propose to call the 
Mangrove zone. Next will come the Coastal Plains ; then 
the Coastal Hills. Still farther inland we come to areas of flat 
or relatively flat land which may be conveniently called the 
Inland Plains. Finally we come to the main range of hills 
forming the backbone of the Peninsula which I propose to call 
the Inland Hills. When opened up and inhabited, each of 
these areas presents special problems. It must not, however, be 
forgotten that in nature all are clothed in primeval forest ; and 
that when inhabited they are in an unnatural, indeed a highly 
artificial, state. The Coastal Plain, in nature, is an alluvial 
flat composed of a heavy clay covered by dense, almost impene- 
trable, jungle. The ground water is almost permanently above 
the surface level; during the wetter months it may be waist 
deep. In some places the clay is covered with a coarse peat, 
formed from slowly decaying vegetable matter. Its depth varies 
from a few inches to many feet. 

Many mosquitoes have their home in this jungle ; but practi- 
cally the only anopheles is A. umbj-osus, which I found to be 

46 



A WORKING RULE 47 

an efficient natural carrier of malaria. I use the word practically, 
for only on one occasion have I found another anopheles in 
this virgin jungle. It was A. aurirostris. There may, of 
course, be others yet to be discovered. 

A. umbrosus, as we saw (Chapter II.), may be present in 
enormous numbers. Generally speaking, it is so abundant in 
houses situated near to this jungle, that it may be obtained 
without difficulty ; for, being a large black mosquito, it is easily 
seen. Sometimes, however, it disappears temporarily even from 
places where it is the rule to find it in abundance. 

As we pass away from the jungle the number of the 
mosquitoes decreases, and at half a mile (or 40 chains) the 
number has so decreased that malaria, as indicated by the 
spleen rate, has disappeared, although occasionally cases of 
malaria do occur. For many years this mosquito has been 
under observation, and its association with malaria studied. 
The sum of these observations is that malaria, in certain 
portions of the district, namely the flat land, is exclusively 
carried by A. umbrosus, which breeds in pools in undrained 
jungle ; and when the jungle is felled and the pools drained, this 
mosquito is exterminated completely; and with its extermina- 
tion malaria disappears. It has been found, too, that the spleen 
rate in the children decreases with the distance they live from 
the breeding-places of the mosquito ; and that the death rate 
of an estate varies as the spleen rate. Finally these facts have 
enabled me to forecast with considerable accuracy the probable 
health or unhealthiness of a proposed site for coolie lines, and 
to give advice which has borne fruit. A theory which will 
provide a sound working rule is one of considerable value. 

In order to make good these statements, I must now refer 
to the individual estates, the positions of which will be seen from 
the maps. In these are seen the parts under cultivation and 
the parts still (1909) undrained jungle. Coolie lines or houses 
are shown by the number, which is the spleen rate for the lines 
or group of lines at that part of the estate. 

Estate "A." — This was opened in 1906, and the coolies were 
housed within 100 yards of the jungle. In 1907 malaria was 
very prevalent among them, and it became necessary to 
administer quinine daily. Rapid progress, however, was made 
in opening up the land ; and within a year there was an 
extraordinary improvement in the health of the estate. The 



48 



THE MALARIA OF THE COASTAL PLAIN 



most striking evidence is to be found in the reports of the 
Indian Immigration Department, from which the following 
figures are taken : — 



















^ 




















w 









Year. 


§1 


5 >5 

S3 


5 


e 

so 
P 



CO 
M 

% 

s 


. 

■g'9 

s ^ 
m 1 ^ 


.— . 
O 

Q 


. 

CO 


bET3 

2" 

S 3 

< 
Ph 


OS 

Pi 


1907 


132 


26l 


12 


34 


125 


12 


183 


78 


120 


100 


1908 


60 


173 


2 


7 


19 




28 


100 


101 


20 



These figures demonstrate the economic importance of 
malaria. The whole success and, in fact, the very existence of 
tropical agriculture depends on a healthy and contented labour 
force. The severe prevalence of malaria in 1907 led not only to 
a high death rate, but to the unnecessary loss, in other ways, 
of about 150 coolies. Coolies will not remain on an unhealthy 
estate; therefore, 34 deserted, 125 gave the legal month's 
notice and left. Instead of having a fine labour force of close on 
300 coolies, the estate had to begin the year with considerably 
fewer than it had the previous year. 

In 1907 the manager, and a friend who had lived with him for 
some time, both suffered severely from malaria. On 23rd July 
1907, only 167 out of 245 coolies were working, and of those 
not at work 10 had high temperatures. Three months later, 
after much loss of labour, I found on one occasion 8 per cent, 
of the labour force with fever, with cedematous feet, and the 
other sequelae of malaria. 

The present manager has been on the estate for nearly 
two years. He has been off work for one day only and that 
not as a result of malaria, a disease from which he has not 
suffered. On 10th January 1910 I examined all the children 
on the estate (it is to be understood that practically every 
child on estates is examined : and that where a spleen rate is 
shown, it is based on the examination of the child population, 
and not merely calculated from an examination of a proportion 
of the children), and out of the fifty-one examined, I found 
one with enlarged spleen, who, inquiry elicited, had come 
from an estate in another district, the death rate of which 
in 1908 was 108 per mille, and which I knew suffered severely 



DETAILS OF ESTATES 49 

from malaria. The child had malaria when it came to 
estate "A." 

I regret I have no figure referring to the children in 1907, 
but I consider the figures I have given demonstrate in the most 
striking way how malaria has disappeared with the draining 
and opening up of the land. Undrained jungle is now about 
half a mile distant from the lines. For its subsequent history 
see Chapter XXI. 

Estate " B." — I first examined this estate in 1904, when all 
the nine children were found free from parasites. There was 
only a small labour force, about sixty in all, and only occasionally 
was there a case of fever. The jungle was comparatively 
near ; but the land immediately behind the coolie lines was 
drained. I find, however, that a small labour force often escapes 
when a larger one is seriously affected. This estate has 
continued to enjoy good health throughout, and on 10th 
January 1910 none of the thirty children on the estate had 
enlarged spleen, and the conductor, who had been there for 
one and a half years, told me he had not had fever. 

The death rates during 1906, 1907, and 1908 have been 
22, 28, and 9 per mille respectively. 

Since I came to know it, this estate has shown continued 
good health, although in 1907 its neighbour, only half a mile 
away, had suffered severely from malaria. 

(1919). — The history of this estate during the subsequent 
ten years has been uneventful, except for an outbreak of 
cholera in 191 1. The following table shows the spleen rates : — 



No. of 


Spleen 


Children. 


Rates. 


3° 


6-6 


64 


7-5 


70 


3-5 



1912 

1915 

1916 

In 1912 two children had come from India two months 
before ; both looked healthy and had not been ill. 
The death rates have been : — 

1909. 1910. 1911. 1912. 1913. 1914. 1916. 1916. 1917. 1918. 

Rate per mille . 14 17 65 25 2 12 3 6 9 52 

In 1918 there was influenza. 

The next four estates, " C," " E," " F," and " G," illustrate 
clearly the association of malaria with undrained jungle. In 



50 THE MALARIA OF THE COASTAL PLAIN 

1909 they were being developed from virgin jungle, of which> 
of course, only a portion could be opened each year. During 
this period of development the labour forces were necessarily 
housed in varying proximity to the jungle; and all four 
suffered from malaria. It will be noted that at any time 
the incidence of malaria was greater the nearer a labour 
force was to the jungle ; and that as the years passed it 
decreased pari passu with the disappearance of the jungle. The 
years in which the various blocks of land were cleared are 
marked on the plan. 

Only part of the story could be told when the first edition 
of this book was written in 1909. Malaria had not yet dis- 
appeared from the upper division of estate " C " ; estate " E " 
was only half-way out of the wood ; the labour forces of estates 
"F"and"G" were still living close to jungle, and still suffer- 
ing from intense malaria. But development was proceeding 
rapidly. It was a period of transition, which can best be 
recalled by reprinting what was written in 1909. Afterwards 
I will bring the story up to date. 

(1909). Estate " C." — This estate began operations in 1904, 
when its labour force was placed on land already opened a 
year or two before by Malays. They were thus placed on 
drained land from the beginning, and accordingly were healthy. 
Its death rate shows this, and was as follows : — 

D. R. 

An experiment was carried out on this estate in 1906 and 
1907, which bore out the extraordinary limitation of the flight 
of the mosquito, the relation of malaria to undrained jungle, 
the importance of selecting the best site for the housing of a 
labour force, and the certainty with which one could predict 
the health or otherwise of a site on the flat land. 

It is an estate of about 3000 acres, and, with the healthy 
labour force it possessed, such rapid progress was made that 
within three years of starting 1000 acres were already opened; 
and it was proposed to open still more. In 1906 much of the work 
of the coolies was one to two miles distant from their lines, 
and it was obviously an economy, both to the estate and the 
coolie, to house him nearer to his work. I was informed in 1906 
that it was proposed to remove most of the force to what 



1904. 


1905. 


1906. 


1907. 


1908. 


25 




34 


37 


13 



DETAILS OF ESTATES 51 

would ultimately be the centre of the estate, which at that 
time was still on the edge of undrained jungle. Knowing 
from experience that the site would probably be very un- 
healthy, I strongly advised that only a few coolies should be 
removed until the land had been further opened up. However, 
four sets of lines were built, three about 25 chains, i.e., quarter 
of a mile from jungle ; and the other about 100 yards. 
The removal took place in October 1906, and on 22nd 
November there were 120 coolies in the lines marked Spleen 
Rate 16, and 80 in a set of lines near to the jungle at quarter 
of a mile from the place marked 80.* The result was 
disastrous. The coolies were overwhelmed with malaria, and 
soon had to be removed. I am indebted to the manager for 
the following : — 

"Re abandoning lines : You ask me my reason for abandon- 
ing four sets of coolie lines in March 1907. They are as 
follows : I found that amongst the coolies living near EE 
drain (place marked 16, about twenty-five chains from the 
jungle) I had 28 per cent, down ill with fever every day, and 
amongst those living near to my bungalow, marked 80 about 

ten chains from jungle, the rate was 33 per cent, daily. 

On that account I removed that portion of my labour force 
to the south-western end of the estate, which had previously 
been healthy, and I abandoned the top lines altogether ; but 
about the beginning of 1909 I put a portion of my labour force 
back again near EE drain, the jungle being then forty chains 
away ; and I am glad to say the fever rate has been very small, 
and of very little consequence. E. H. KlNG-HARMAN." 

On 22nd November 1906, there were fifteen children in the 
lines marked 16, of whom only one had enlargement of the 
spleen. On 17th February 1907, there were twelve children, 
of whom seven, or 58 per cent., had enlarged spleens. 

As these were the same children, it shows how malarious 
the place had become. 

On 4th January 1909, there were fifteen children living in 
the same place, of whom three had enlargement (very small 
in the case of two), equal to 20 per cent. A portion of the 
force had only recently been removed to the edge of the 

* The place marked 80 on estate " C " does not represent a spleen rate, 
but only the number of coolies there in 1906. Coolies no longer live on this 
site as it was so unhealthy, and the lines were destroyed. 

F 



52 THE MALARIA OF THE COASTAL PLAIN 

drained jungle on block II, so that the figures for the whole 
division were thirty children, of which five, or 16 per cent, 
had enlarged spleens. 

Now on the south-western portion of the estate, that is the 
portion of the estate first occupied in 1904, I examined, on 
5th January 1910, the children— in all 109. Of these, four 
had enlarged spleen, giving a spleen rate of 3-6. They 
were recent arrivals. I recognised two sisters as being 
the only two children who had been found with enlargement 
on an estate in the neighbourhood ; one other had come two 
months previously from an estate in another district ; and one 
had come from an estate where the spleen rate was 100. The 
corrected spleen rate should therefore be nil. 

The bungalow to which the manager refers is still in 
occupation, and malaria is far from unknown to its occupants ; 
while the bungalow on the south-western division has never 
been infected with malaria. 

The medical history of this estate has been practically that 
of a series of experiments of the most convincing character. 
If any doubt remained, a glance at the map showing the 
condition of the estates marked " E," " F," and " G," the coolie 
lines of which at the present moment vary in distance from 
jungle which has been drained for about one year only. The 
lines marked 23 had undrained jungle to within 200 yards 
about a year ago. Jungle is now about 500 yards distant, 
and it has been drained for about four months. The lines 
marked 59 on estate " F " are opposite and within fifty yards 
of jungle, which, however, has been drained for some months. 
The percentage of children with abnormal spleens was 59, 
based on the examination of thirty-two children. Of the 
thirteen with no enlargement, one has been one and a 
half years on the estate, three had been only fourteen days, 
while the others had been less than six months. It is interest- 
ing to note that the jungle opposite had been drained for 
about the same period, and this probably accounted for these 
children having escaped. Dr T. S. Macaulay kindly examined 
the blood of twenty children on this estate, and found parasites 
in seven, or 319 per cent. These children got about 5 grains 
of quinine daily. 

On 6th December 1906 I examined three children on this 
estate, and of these two had considerable enlargement of the 



DETAILS OF ESTATES 



53 




Emery Walker Ltd. sc 



Fig. 14.— Plan of Estate "C." 



54 THE MALARIA OF THE COASTAL PLAIN 

spleen. The death rate of the estate in 1908 was 41 per 
mille. 

Estate "G" has been unhealthy since it was opened, as 
undrained jungle has always been within less than 100 yards 
of all the coolie lines. 

On 5th January 1910, I examined twenty-four children on 
this estate, and of these fifteen had enlarged spleen, equal to 
62 per cent. Of the nine with no enlargement, two had been 
only fourteen days on it ; and one had a high temperature at 
the time of my examination. 

Dr Macaulay examined the blood of eleven of the children 
on this estate, but did not find parasites. All were on quinine, 
about 5 grains daily. 

On 6th December 1906, I examined eight children on this 
estate and found three, or 37 per cent., with enlarged spleen. 
The death rate given in the Indian Immigration Return is 
69, but this does not represent the exact death rate, since 
estate " M," which belongs to the same Company, had an 
estate hospital, to which the sick from this estate were sent. 
Those who died there were not accredited to " G," but swelled 
the death rate of estate " M," to an unnatural degree. I will 
draw attention to this later. 

From these figures it is evident that the opening up of the 
estates "F" and "G" did not lead to any improvement in 
their health ; and the reason was obviously that the lines 
were still as near to the jungle as when the estates were first 
opened. This is in marked contrast to the improvement to 
be seen where the opening of the estates pushes the jungle 
away from the lines. 

(1919). — Such were the conclusions reached in 1909. If 
they were correct, and if jungle swamp was the cause of the 
malaria, then the health of estates " F " and " G " could not 
be expected to improve until they moved their labour forces 
away from the block of jungle marked III or until the jungle 
was opened up. Time proved the conclusions to be correct. 
In due course the jungle was opened : so too were the blocks 
marked I, II, IV, and V. Then, and not till then, the high 
spleen rates fell, as the following records show. Jungle Block 
I was opened in 1907, block II in 1909, and blocks III, IV, 
and V in 1910. 



EXAMINATION OF CHILDREN ON FLAT LAND 

Spleen Rates of Estate " C." 

Lower Division. Lines never near to jungle : — 

Year. 
1910 

1913 
I9IS 

1917 
Upper Division. Line 100 to 400 y 



55 



Year. 
1909 
1913 
1917 



No. of 
Children. 




Spleen 
Rates. 


109 




3-6 


237 




1-2 


221 




17 


306 




2*2 


from jungle 


in 19c 


No. of 
Children. 




Spleen 
Rates. 



30 16 

109 27 

. 138 3-6 

The death rates of Estate " C " from 1906 onwards have 
been as follows 1—34, 37, 13, 3, 11, 13, 15, 7, 5, 8, 13, 23, 31, 12. 

Spleen Rates of Estate " E." 

Lines 200 yards from jungle in 1908 : 

Year. 
1909 
1911 

1913 

1915 
1917 

Spleen Rates of Estate " F.' 

Jungle next to lines drained in 1909 : — 

Year. 
I906 
I9IO 
I912 
1913 
1915 
1917 



No. of 


Spleen 


Children. 


Rates. 


13 


23 


18 


1 i-i 


20 


15 


31 


107 


39 


2-5 



No. of 
Children. 

3 


Spleen 
Rates. 
66 


32 


39 


32 


24 


92 


2-1 


76 


14.4 1 



4-8 



* Included eight children from malarious estate. 

Spleen Rates of Estate " G." 
Jungle next to lines drained in 1909, and planted in 1910 : — 





No. of 


Spleen 


Year. 


Children. 


Rates. 


1906 


8 


37 


I910 


24 


62 


19II 


62 


6 


I9'3 


no 


1-8 


1915 


76 


11 


f February . 


. 118 


2 


1917 1. September 


1 11 


10 



56 



THE MALARIA OF THE COASTAL PLAIN 



So we see how hundreds of healthy children now live 
on places which only a few years ago were most malarious. 
Further comment on the figures is superfluous, beyond a 
reminder that just as the labourer is free to leave a healthy 
estate when attracted by the higher wages of an unhealthy one, 
so he often returns when ill, and he and his sickly children 
raise the death rate and spleen rate of the healthy estate. 
For example, eight of the eleven children with enlarged 
spleen found on estate "F" in 191 5 had recently come from 
an unhealthy estate. It is easy to ascertain a fact like that, 
and so the correction of spleen rates is easy. In the course 
of this book, many such' instances occur. As it would merely 
burden the narrative unnecessarily to give details in every 
instance, it will be done only in some. 

Estate "//." — The medical history of this estate can be 
found from the subjoined table. 





1904. 


1900. 


1900. 


1907. 


1908. 


1909. 


Blood examination — 
Number examined 
Percentage infected 

Spleen examination — 
Number examined 
Percentage enlarged 
Death rate . 


25 
28 


13 
4« 


27 
O 

27 

O 

3° 


30 


22 


26 
O 

58 

1-6 



Now from these figures it is obvious that a marked 
improvement occurred in the health of this estate in 1906. 
I give in the manager's own words the explanation : — 

" In answer to your inquiry with regard to the health 
of this estate : In 1904 only 160 acres were opened and jungle 
came comparatively close to the lines. There was so much 
fever that coolies had to be dosed with quinine daily at muster. 
Little opening was done during 1905, and the state of health 
among coolies remained much the same : in 1906 jungle was 
carried back by opening to a distance of one and a quarter 
miles on one side and about half a mile on the other, and from 
that date there has been practically no fever on the estate 
and the out-turn of coolies daily has improved to a marked 
extent. Dated S/1/10. N. C. S. Bosanquet." 

Comment on this is hardly necessary, but I might mention 
that the lines were distant from the jungle in 1904 about 



EXAMINATION OF CHILDREN ON FLAT LAND 57 

a quarter of a mile. The extra quarter of a mile made all the 
difference. Being a quarter of a mile away to begin with the 
estate was not suffering so severely from malaria as would 
have been the case had the lines been closer, but I think the 
lesson can hardly be missed. 

(1919.) — The health on this estate has continued good. 
Malaria has never returned. 



Year. 
19II 
1912 
1914 



Spleen Rates of Children. 



No. 


Spleen 


Spleen 


Examine*]. 


Enlarged. 


Rates. 


73 


3 


37 


83 


2 


2-4 


66 


2 


2-7 



The death rates per mille have been equally satisfactory ; from 
1906 inclusive they have been: — 30, 30, 22, 5, 13, 24, 14, 10, 2, 
8, 23, 20, 15. 

Estate "I." — Opened in 1904, this estate suffered very 
severely from malaria, more so than the percentage of children 
infected in 1905 would lead one to suppose. It was so severe 
that not a child below the age of one year was to be found 
on the estate; although the adult labour force was then about 
250. The manager suffered so severely from the disease that 
he had to be sent on three months' leave of absence. In 
December 1905, I saw no fewer than seventeen coolies, or 6-8 
per cent, of the whole labour force ill with malaria fever, while 
diarrhrea and dysentery, the common terminal sequelae of 
malaria, were far from uncommon. Then, in 1906, opening 
up having been continued, improvement took place. The 
present manager had been on the estate for over three years 
and had not had malaria. 

Table giving Particulars of Estate "I." 





1905. 


1906. 


1907. 


1908. 


1909. 


Blood— 

Number examined 
Percentage infected 

Spleen — 

Number examined 
Percentage enlarged 
Death rate 


15 
26 


16 


68 




54 


59 
1-6 

58 

i-4 



58 THE MALARIA OF THE COASTAL PLAIN 

The jungle is now (1909) rather less than half a mile from 
the lines. 

(1919). — In subsequent years the jungle was pushed back 
still farther, and the good health was maintained. In 1913 
there were eight children with enlarged spleen out of 129 
(6-2 per cent.); in 191 5, two children out of 177 (i-i per cent.). 
Further comment is superfluous. 

(1909). — We have thus seen that, on the same road on two 
different estates, the lines, which were near to the undrained 
jungle, were unhealthy; and that when the jungle was pushed 
back, the lines became healthy. Yet there has been no general 
change in the country ; for we find that, at the present date 
(1909), we have only to go to the lines still on the jungle 
edge to find malaria. Immediately inland from estate " I," 
we come to estate "J"; and here of the nine children, four, 
or 44 per cent, have enlarged spleens. Quinine was given 
systematically on the estate, and doubtless this kept the death 
rate comparatively low. It was thirty-four per mille in 1908, 
and 120 in 1907. 

(1919). — The jungle next to the coolie lines on estate "J " 
is still there. It is now reduced to a strip 80 chains wide ; on 
both sides and at the ends, the land has been opened, drained, 
and cultivated for long distances. The jungle grows on a 
clay, covered by a deep layer of peat ; in very wet weather, 
water stands on the surface, so only during a short period of 
the year is it a breeding-place for anopheles. The result is 
that the health of estate "J" has materially improved; some- 
times, in the wet months of the year, a few malaria cases 
appear ; but the low spleen rates show how little there is. 

Spleen Rates of Estate "J." 

Year 

1909 . 

1913 . 

1915 . 

1917 . 

1919 . 

A similar condition of health exists on another estate close 
to estate " J " and similarly close to jungle. Out of twenty 
children examined not one had an enlarged spleen ; but malaria 
does occur at times in the wet months. 



No. of 
Children 
Examined. 


Spleen 
Rates. 


9 


44 


41 





34 





41 


4-8 


61 






DISAPPEARANCE FROM CERTAIN AREAS 59 

(1909). — The story of how malaria has disappeared from 
estates on flat land, as the jungle has been pushed back to 
about half a mile, little short of miraculous as it is, becomes 
monotonous as we trace it north up to Kuala Selangor, and 
down south through Klang to Kuala Langat, over a distance 
of some fifty miles. The maps, indeed, tell the tale. I would 
gladly leave it at that, but the subject is of such economic 
importance that I must make the proof of the improvement as 
full as possible. For, marvellous as the disappearance of malaria 
has been with the opening up of the flat land, just as striking 
has been the total failures of similar opening to affect malaria 
on the hilly land. The explanation of the difference is to be 
found in the mosquito theorem ; that alone can explain it. 
On the flat land the carrier of malaria is the mosquito, 
A. umbrosus, which, breeding in pools in the jungle, is extermi- 
nated when these pools are drained even by open drains ; 
while on the hill land, the chief carrier is A. maculatus, a 
mosquito which cannot be exterminated in the ravines by open 
drainage, however quick the current, since its proper breeding- 
place is the running water of springs and hill streams. 

My object, therefore, even at the risk of being tedious, is 
to show that on flat land the manager of an estate can put 
his coolie lines, in almost every instance, beyond the reach 
of the malaria carrier, and so save his labour from malaria ; 
and I maintain that, since over thousands of acres of flat land 
malaria has been abolished by extermination of the mosquito 
which carries the disease, so the manager of the hill estate 
can also abolish the disease if he abolishes the breeding- 
places of the hill-carrier by putting the water of the ravines 
underground. 

Estate" K" is small, and I have few figures referring to it. 
Its coolie lines have always been at a distance from jungle, and 
have always been healthy. I am indebted to Dr Macaulay 
for examining the fourteen children on this estate. Of the 
fourteen he found one with an enlarged spleen, equal to 7 per 
cent. This child, however, came from an estate on which the 
spleen rate is 23, and had suffered from fever before coming 
to estate " K." The death rate of this estate was 18 per mille 
in. 1 908. 

(1919). — In 1912 and 1916 the number of children examined 
was 30 and 129 respectively. No enlarged spleen was found 



eo 



THE MALARIA OF THE COASTAL PLAIN 



on either occasion. The health of the estate has remained 
uniformally good. 

(igog).— Estates " L," " M," " N," " O," " P," " Q."— Their 
spleen rates, as given on the map (p. 68), show that those away 
from the jungle are healthy, while those close to it are more 
unhealthy ; and that, even on the same estate, there are marked 
differences of health depending also on the proximity or other- 
wise of the lines from the jungle. Estates " L," " M," " N," " O " 
are all at some distance from the jungle, and all are healthy. 
Estate " P " has some lines near to the jungle, and these are 
very unhealthy ; while others away from it are healthy. 
Estate " Q," on the other hand, had all its lines close to jungle 
until recently, and some remain so ; and its spleen rate is 
high. 

Dealing with these estates in detail, we find that during 
the course of the past few years some of those, which are 
now healthy, were unhealthy when the lines were closer to 
jungle. 

Estate " L." — This estate, begun in 1902, had already a 
considerable area opened and drained by November 1904, when 
I first made an examination of the children. 



Table showing the result of Blood and Spleen Examination of 
Children, and the Death Rate of Estate "L." 





1904. 


1905. 


1906. 


1907. 


1908. 


1900. 


Blood— 

Number examined 
Percentage infected 

Spleen — 

Number examined 
Percentage enlarged 
Death rate . 


10 

33 


16 
6 


18 
O 

18 



20 


21 


39 
2-5 



Dr Macaulay, to whom I am indebted for the examinations 
in 1909, says that of the thirty-nine children, the only one with 
enlargement of the spleen was a child eight months old, born 
on the estate. The enlargement was so slight that he could 
hardly call it pathological. 

Here again we see the improvement which has followed 
the abolition of the malaria carrier, for A. umbrosus can no 
longer be found on this estate. 



DISAPPEARANCE FROM CERTAIN AREAS 61 

(1919). — In 1912 there were ninety-five children on the 
estate, none of whom had enlarged spleens. 

Estate "A/" was first opened in 1898, and I cannot recall 
the time, since I came to the district in 1901, when it was 
unhealthy. Such figures as I have show this : — 



1905. 


1006. 


11107. 


1908. 


1909. 


Blood— 

Numher examined 
Percentage infected 

Spleen — 

Number examined 
Percentage enlarged 
Death rate 


26 
3 


25 

4 

25 
4 


15 


26 


202 

3-4 

35 



The death rate of this estate is shown as larger than it should 
be since coolies sent from estate " G," who died in the estate 
hospital on " M," have been counted in this death rate. 

That the estate is free from malaria is shown by the fact 
that no European has contracted malaria on it since I came 
to the district ; and there is now, and has been for several 
years, a European staff of six. 

(1919). — The following table shows the spleen rates : — 



Year. 


No. Examined. 


No. Enlarged. 


Spleen Rates. 


1912 
1914 
1916 


57 
138 
128 


I 
6 
3 


i-7 
4-3 

2-3 



The Europeans have continued to be free from malaria. 

Estates " N" and " O."— The lines of both the estates are 
now a considerable distance from the jungle, the nearest being 
the mangrove, which is 600 to 1000 yards off. 

I have few figures concerning these estates. I remember 
on one occasion in 1905 visiting a set of lines on "N" and 
found many cases of fever. It was then within 100 yards of 
the jungle. Unfortunately, I cannot find my notes of this. 

The following figures show that the estates are not by any 
means unhealthy. The labour force is small on each, being 
only 280 on " N " and 120 on " O " : — 



62 



THE MALARIA OF THE COASTAL PLAIN 





Death Rates. 


Spleen Rates, 1909. 


1906. 


1007. 


190S. 


No. 
Examined. 


Percentage 
Enlarged 


Estate " N " . 
Estate "0" . 


8 

44 


20 

18 


43 
34 


29 

45 



2-2 



Estate " P " is one of the largest in the country, and 
stretches over several square miles. Within its boundaries are 
to be found lines at varying distances from undrained jungle. 
These show in the most distinct manner what has been evident 
on all the other estates to which I have previously referred. 

It will be seen from a reference to the map, that the lines 
82 are close to the jungle. They contained seventeen children, 
of whom fourteen had enlarged spleens. Farther along, on the 
edge of the same jungle, are lines containing eleven children — 
of whom ten have spleens abnormal in size, giving a rate of 
909. Two hundred yards from these the lines containing 
fifteen children showed a spleen rate of 5 3-3, while at a dis- 
tance of 300 yards from the lines marked 82 the spleen rate 
of twenty-two children was 599. 

In marked contrast to these are the 109 children who live 
at a greater distance from the jungle and whose spleen rate is 
8-2. That it should be so high as this is due to some of the 
lines being near to a small belt of jungle once drained — but 
whose drains are not upkept. When the lines were put there 
in 1906 I have notes showing that there were considerable 
numbers of cases of malaria on the estate, and I recollect that 
these were unhealthy ; but, unfortunately, I have not recorded the 
exact number of cases found in each of the different sets of lines. 
There is no doubt, however, that these lines next to the belt of 
jungle have improved in health to a very considerable extent. 

In tabular form these facts become more evident : — 



Distance from Undrained Jungle. 





Within 
100 yards. 


200 to 300 
yards. 


Beyond 
000 yards. 


No. Children examined . 
No. with enlarged spleen 
Percentage with enlarged spleen 


28 
24 
857 


37 

17 

45-9 


109 

9 

8.9 



EXAMINATION OF CHILDREN ON FLAT LAND 63 

For the subsequent history of estate " P," see Chapter XVI. 

Estate " Q." — The lines on this estate also vary in distance 
from one hundred yards to a quarter of a mile from the jungle. 
I found, however, that the coolies had been moving from the 
lines nearest to the jungle to others farther away. I, therefore, 
cannot determine with accuracy the spleen rate of the different 
lines. The lines a quarter of a mile from jungle have a spleen 
rate of 28 ; while that of those within 100 yards is 59-3. 

The other rates are 55-5, 429 and 60, and that for the whole 
estate is 53-6. 

The death rate was 60 per 1000 in 1908. For the later 
history see Chapter XVI. 

Estate " R." — Within 150 yards of the lines on this estate is 
a small swamp about half an acre in extent. There is no other 
swamp within half a mile. 

Of nineteen children examined in 1910, 10-5 per cent, had 
enlarged spleen. The death rate of the estate has been 40, 
56, and 45 in the years 1906, 1907, and 1908 respectively. 

(1919). — There are other two records of the spleen rate of 
this estate. In 1915 and 1916 there were 32 children ; on each 
occasion one child had enlarged spleen, giving a rate of 3-2. 
The child had returned to estate " R " after having bolted to 
an unhealthy estate. 

Passing south across the Klang River we come to estate 
" 5 " which has been opened for some years. Although ex- 
tensive in area, the opening has not been such as to decrease 
the distance of the lines from the nearest jungle. The following 
table gives the facts : — 



Distance 


of the Various Lines from 


Jungle. 






200 yards. 


300 yards. 


350 yards. 


300 yards. 


-00 yards. 


No. examined 
Spleen rates . 


4 
5° 


7 
28.5 


13 
23-0 


S 

37-5 


20 
20 



There has been a great improvement in the health of this 
estate during 1909 due to the extensive use of quinine. It is 
an example of how quinine may appear of greater value in a 
place where malaria is not very severe than where the disease 
is intense. 



64 THE MALARIA OF THE COASTAL PLAIN 

The estate has always been unhealthy, but not intensely 
malarious, the spleen rate of the whole estate being only 23 ; 
still the disease has caused considerable trouble. There are 
no official figures for 1907, but in that year the manager was 
invalided to Europe on account of malaria. In the same year 
a large gang of coolies also left on account of the disease. In 
1908 there was great sickness ; and I saw many cases of chronic 
and acute malaria on the estate. In the months of November 
and December, no fewer than sixteen coolies died from malaria 
and its complications. The whole labour force was then put on 
to quinine — ten grains daily, and the death rate at once came 
down. Of the six deaths in 1909, none was due to malaria 
either directly or indirectly. The figures are interesting : — 



Year. 


Average 
Population. 


Deaths. 


Desertions. 


Discharges. 


Total Loss. 


1908 
1909 


362 

373 


42 
6 


137 
46 


230 
172 


409 
224 • 



This is the only estate on which quinine is given systemati- 
cally, the spleen rate of which is below 40. I refer to the subject 
of the dose of quinine in relation to the intensity of the disease 
on p. 119. 

(1919). — The subsequent history of this estate is of great 
interest, as is that of another estate subsequently opened 
beside it. It will be found in Chapter XXII. on the Reappear- 
ance of Malaria. 

(1909). — The next two estates, "T" and " U," I deal with 
together, as they form practically one clearing in the middle of 
jungle. 

On Estate " T" one set of lines is close to jungle, about 
50 feet from it, and of three children all have enlarged spleens ; 
while, in the set of lines 100 yards from jungle, nine out of ten 
have enlargement. The spleen rate of these two sets of lines is 
therefore 92-3. 

The other lines on the two estates are close to each other, 
and about one-third of a mile from jungle Of the fifty-four 
children twenty-one suffer from enlargement, giving a spleen 
rate of 38-8. 

The rate of the whole sixty-seven children on the two 



EXAMINATION OF CHILDREN ON FLAT LAND 65 

estates in 1909 is thus 492. On the 16th January 1907, I 
examined forty-four children on these same estates and found 
twenty-six with enlarged spleens, giving a rate of 59. It will 
thus be seen that here again the lines near to the jungle 
are the more unhealthy, and that during the last three years, 
because the nearest jungle is still at the same distance from 
the lines, there has practically been no improvement in 
the health. The death rates bear this out. 





11106. 


1007. 


1908. 


Estate "T " . 
Estate "U". 


72 
37 


33 
64 


107 

75 



(1919). — Development has proceeded rapidly since that was 
written in 1909. Except for a small area of perhaps 5 or 
6 acres, no jungle exists within three-quarters of a mile of 
the lines : in many directions it is over a mile away. The 
health has improved according to rule. In 1919 the spleen 
rate of 177 children on estate " T " was 16 per cent. 

(1909). — Estate " SSS," a small clearing in the jungle, follows 
the usual rule. No coolies can be kept on it, as it is so unhealthy. 

Turning back towards the coast we come to the estates 
" V," " X," " Y," " AA," " BB," " CC," which are among the 
oldest in the district, and have large areas opened up. On 
all, with one exception, the lines are at a distance from jungle, 
and the health of all is good. It was not, however, always so. 
I remember, when District Surgeon, that cases of malaria 
were not infrequently admitted from estate "V"; while in 
the first half of 1 906 I find from my notes that malaria was 
constantly seen in the lines of estate " X," which are marked 7, 
and which were then on the edge of the jungle. I have, 
however, no figures referring to the children. 

The following table shows their present condition : — 





■1 v » 


"X." 


"Y." 


"AA." 


"BB." 


"CC." 


Number examined . 


32 


85 


145 


26 


25 


82 


Spleen rate 


9.6 


7-0 


4.8 





4 


3-6 


Death rate, 1908 


II 


30 


29 


22 


22 


9 


,. 1907 


6 


2S 


35 




20 


30 


„ 1906 





67 


23 


38 


20 


30 



66 THE MALARIA OF THE COASTAL PLAIN 

It is hardly necessary to comment on these figures. But on 
estate " V," of the three coolies with enlarged spleens, one came 
from a set of lines on another estate the spleen rate of which is 
over 50. In April 1909, Dr Stanton, of the Institute for Medical 
Research, examined 160 unselected coolies on this estate, and 
found only two, or 13 per cent., with malaria parasites in the blood. 

Although the estate is classed among those of the flat land, 
it is not entirely flat. Part of it is hilly. The absence of 
malaria is due to the valleys between the hills being of such 
a formation that no proper hill streams are found, and 
A. maculatus cannot be found either in the drains or in the 
lines of the estate. Klang Town is also hilly, but here again 
there are no hill streams in which A. maculatus breeds.* 
Hence open drains sufficed to eradicate malaria. An idea was 
prevalent among medical men at one time that malaria was due 
to a disturbance of hill soil, the exposure and excavation of 
red earth, and the quarrying of laterite. 

The absence of malaria from estate " V," where red earth 
and laterite are abundant, from the town of Klang where the 
constant quarrying of laterite and the excavation of red earth 
have gone on for years, from the midst of the town and at 
the hospital, shows that malaria is not due to the presence or 
disturbance of these soils. The one constant condition which 
I have found associated with malaria is the presence of certain 
species of anopheles. It is true that, in some of the most 
malarious places, it is said by the layman that there are no 
mosquitoes. On one such place, an estate where the spleen 
rate is 100 and the death rate in 1908 was 300 per mille, the 
manager, a man of more than ordinary intelligence, assured 
me that mosquitoes were never seen except on a wet night, 
and then only in small numbers. My experience was that, 
whereas the man who helps me to catch mosquitoes usually 
earns 20 or 30 cents in a couple of hours, being paid at the 
rate of 3 cents for each anopheline, on this estate he earned 
3 dollars and 12 cents in the same time, and at the same 
rate; having thus caught 104 anophelines. When I went 
to the lines I found the mosquitoes, mostly A. maculatus, in 
great abundance. A. maculatus is a small mosquito ; it makes 
little noise and causes little, if any, pain when it bites. This is 

* In 1913 A. maculatus appeared in the hill-foot drains. (See Chapter 
XXII.) 



EXAMINATION OF CHILDREN ON FLAT LAND 67 

different from A. umbrosus, which gives a painful bite something 
like a sharp hot needle. 

(1919). — The town of Klang and estates "V" and "X" 
remained free from A. maculatus until 1913. Fortunately for 
estate " V " they came mainly to a small ravine more than 
half a mile from the coolie lines of the estate ; unfortunately for 
estate "X" they were within 100 yards of its lines, in which they 
produced a serious outbreak of malaria. (See Chapter XXII.) 

Estate " V" continues to be healthy as the spleen rate 
shows. 

Spleen Rates of Estate " V." 



Year. 


No. Examined. 


No. Enlarged. 


Spleen Rates. 


1915 
1918 


73 
79 


5 

2 


6.8 

2-5 



(1909). — Of the six children on estate " X " with enlarged 
spleen, three had been on the estate only fourteen days, having 
come from India. The presumption is that these children had 
malaria before their arrival on the estate. The high death 
rate of this estate in 1908 was due to the return to the estate 
of a gang of coolies, eighty in number, who had gone to an 
estate whose spleen rate is 100. They suffered so severely 
from malaria there that they returned at the end of six weeks. 

The manager of estate " X " was afraid these coolies might 
infect the others, but this did not occur since there was no 
anopheline to act as carriers. 

On Estate "Y" seven of the lines were close to jungle, which, 
although drained on the two sides which are close to the lines, 
could not be called properly drained. Three years ago, how- 
ever, I was unable to find anophelines in it on one single 
occasion. Of the ninety children in these lines 5-2 per cent, 
had enlarged spleen, while in another set of lines close to 
drained jungle twenty-two children showed a spleen rate of 8-3. 
The spleen rate of the remaining thirty-three children who 
were housed about half a mile from the jungle was nil. 

This is the only estate which even appears to be an 
exception to the rule that lines within 200 yards of the 
jungle should have a spleen rate of about 50, but the presence 
of a large 1 5-foot drain along one side of the jungle and a 6-foot 

G 



68 



THE MALARIA OF THE COASTAL PLAIN 



KUALA LANGAT DISTRICT 



69 



drain along the other side, as well as the fact that the jungle 
here is peaty, probably explains the freedom from sickness. 

(1919). — At times large numbers of A. umbrosus temporarily 
appear in the lines and bungalows of this estate. 

Estate " EE," see Chapter IX. Estate " CC" see Chapter 
XXII. 

(1919). — The health of Estate "BB" has continued to be 
excellent; the spleen rate in igr 5 was 1-36 (-2-8 per cent.). 
The death rates from 1907 to 1918 inclusive have been 20 to 23, 
19, 21, 25, 7, 8,0, 3, 16, 8, and 19. 

(1909). — Passing on to the Langat District again, we come 
to a small estate, "///," the lines of which are a little over a 
quarter of a mile from jungle. The spleen rate of the twenty- 
one children is 14. The death rate in 1908 was 19 per mille. 

(1909). — The next estate is " FF," and in the lines next to 
the jungle the rate is 33, while in the more distant lines it is 
nil. For the whole estate it is 23-7, and the death rate for 1908 
was 53 per mille. 

(1919). — As years passed the estate grew in size ; the labour 
force was housed in three different areas or divisions, the latest 
still farther from the jungle than the other two. I shall call 
them Divisions I., II., and III. 

Division I. next to the jungle maintained its high spleen 
rate ; and each wet season saw a number of malaria cases, 
with rarely a death ; for more than ordinary care is taken with 
this labour force. The chief difficulties in making the estate 
healthy were a special jungle reserve for " Sakais," one of the 
native races of the Peninsula ; and the prohibitive prices the 
surrounding natives placed on patches of swampy kampongs. 

In 191 5, however, the kampongs were cleaned up and 
drained, and by 1917 the estate had reaped the benefit of 
these measures as the following figures show. 



Spleen Rates of Estate "FF." 



Year. 


No. Examined. 


No. Enlarged. 


Spleen Rates. 


1909 


13 


3 


23 


1915 


56 


18 


32 


1917 


99 


5 


5 



70 



THE MALARIA OF THE COASTAL PLAINS 



These figures are for the whole estate. It is not necessary 
to go into details : they simply show that as long as the spleen 
rate of the estate was high, it resulted from the children living 
next to the jungle. Division III. was from the first free from 
the disease. 

(1909). — Farther on, Estate " GG" has a spleen rate of 2-2 
(fifty-nine examined), although the lines are a quarter of a mile 
from jungle and separated from it by a river. On this estate 
were eighteen children, of whom ten had enlarged spleen. 
These came from an estate whose rate is about fifty. By 
deducting these children the corrected rate of the estate would 
be 7.3. 

The death rate of the estate in 1908 was 31. It has been 
healthy from the beginning as it began on open land. 

(1919). — Nothing much of note has to be recorded: the 
health has continued to be good. The spleen rates have 
been : — 

Spleen Bates of Estate " GG." 



Year. 


No. Examined. 


No. Enlarged. 


Spleen Rates. 


1914 (May) 

1914 (Dec.) 

1917 


32 
H3 
138 


4 
3 



12-5 

2-6 




Of the four children found with enlarged spleen in 1914, 
three belonged to a family which had left the estate for a time 
to live at Jugra Hill, a very malarious place (see p. 183); 
there the father died of malaria ; the widow and children then 
returned to the estate. 

At the muster in 1917, I was interested to see three of the 
eighteen children, mentioned as having come from a malarious 
estate in 1909, now mothers with healthy babies in their arms. 

(1909). — In marked contrast to this is the next Estate 
"HH" only half a mile farther on; where all the lines are 
within a hundred yards of jungle. Of forty-six children 54-3 
per cent, had enlargement of the spleen, and in 1908 the death 
rate of the estate was correspondingly high, namely 60 per 
mille. 

(1919). — In 1909 "HH" was an estate of only a few hundred 
acres ; to-day there are over 4000 acres, except for a narrow 



KUALA LANGAT DISTRICT 71 

strip of swampy jungle on the stiff clay soil of the river bank, 
jungle is everywhere distant from the lines. 

Spleen Rates. 



Year. 


No. Examined. 


No. Enlarged. 


Spleen Rates. 


1909 
1915 
1917 


46 
200 

257 


25 
6 

9 


54-3 
3-o 
3-3 



Five out of the nine children with enlarged spleen were 
among 42 on the division nearest the strip of jungle on the 
river bank. 

(1909). — Estate " TT" has a spleen rate of only 13 in the 
fifteen children examined. The lines are about 200 yards from 
jungle, but are separated from it by a river. Its death rate in 
1908 was 47. 

(1919). — The jungle on both sides of the river is now 
opened ; in fact, a portion of the labour force now lives on the 
opposite bank. 

Spleen Rates. 



Year. 


No. Examined. 


Spleen Rates. 


1915 

1917 


80 
126 


o-o 
1-5 



Both children with enlarged spleen in 1917 were on the 
old division. 

(1909). — The following three estates again corroborate the 
evidence which we have been so steadily accumulating. Estate 
" JJ" nas lines within a quarter of a mile of jungle and the 
spleen rate of fifty-three children is 26-3. Its death rate was 
39. The figures tell their own tale. 





Distance Lines are 
from Jungle. 


Spleen Examination. 


Death Rate, 
1908. 


No. 
Examined. 


Percentage 
Enlarged. 


Estate 
u 
11 


"jj" . 

"KK" . 
'LL" . 


400 yards 
Over 1000 yards 

V )! 


53 
48 
70 


26.3 

o-o 
1-4 


39 
12 

17 



72 



THE MALARIA OF THE COASTAL PLAIN 



The only child found on estate " LL " with enlarged spleen 
had come from an estate whose spleen rate was between 30 
and 40. 

(1919). — All three are now free from malaria; no jungle is 
near to any of them. 



Year. 


Estate " JJ." 


Estate "KK." 


Estate "LL." 


No. 
Examined. 


Rate. 


No 
Examined. 


Rate. 


No. 
Examined. 


Rate. 


1914 

1917 (Jan.) 

1 91 7 (Oct.) 


I 
If 


2 

>5 


0.8 

1-2 


135 
135 
155 


0.7 
00 
o-o 


209 
226 
246 


1-4 

0.8 
o-o 



The examinations in 1917 were by different European 
observers. 

(1909). — Adjoining estate " KK" are two estates illustrating 
the same rule. Estate " PP" is a small one, but the manager 
and his coolies suffer considerably from fever. The two children 
on it had both enlarged spleens. They all live within a hundred 
yards of jungle. 

In due course the jungle was opened up and health improved. 

Spleen Rates. 



Year. 


No. Examined. 


No. Enlarged. 


Spleen Bates. 


1915 

1917 


41 
63 


3 



7-3 
00 



The three children with enlarged spleen belonged to one 
family, which had arrived from India only \\ months previously. 

(1909). — Estate "00" has lines in two places. One set of 
lines is now half a mile from jungle, but until recently the 
jungle was only a quarter of a mile away. The other set of 
lines are, and have been, half a mile from jungle for about two 
years. The result is very striking ; for, whereas in the lines 
which were until recently a quarter of a mile from jungle, 60 
per cent, of the twenty-eight children examined suffered from 
splenic enlargement ; of the seventeen in the other lines, the 
spleen rate was nil. 



KUALA LANGAT DISTRICT 



73 



(1919). — Here, too, with the development of the estate, 
the jungle was pushed farther from the lines and the health 
improved. 

Spleen Rates. 



Year. 


No. Examined. 


Spleen Rates. 


1915 

1917 


177 
130 


0-5 
0-7 



The only child with enlarged spleen in 1917 had come from 
Seremban (an unhealthy district) one month before. 

The death rates from 1907 to 1918 inclusive have been: — 
40, 40, 21, 29, 27, 15, 14, 13, 2, 7, 12, 17, the last being the year 
of the influenza pandemic. 

(1909). — Until recently the lines on Estate " NN" were one 
third of a mile from jungle. The spleen rate of the thirty-five 
children is 11-4; while the lines of Estate "MM" are over 
1000 yards from jungle and none of the twelve children have 
abnormality of the spleen. 

(1919). — Estate " MM " continued healthy — the spleen rates 
being : — 



Year. 


No. Examined. 


Spleen Rates. 


1915 

1917 


121 

131 


2-4 
07 



Estate " NN " is now one of the largest in the district ; it is 
divided into two divisions a few miles apart. The spleen rates 
have been : — 



Year. 


No. Examined. 


No. Enlarged. 


Spleen Rates. 


1909 

1917 (Jan.) 

1917 (Dec.) 


35 
238 

190 


I 

2 


II.4 

0.4 
1-0 



The girl with enlarged spleen in January 1917 had recently 
come from India. She had not suffered from fever on the 
estate, and had worked regularly without missing a day. At 



74 THE MALARIA OF THE COASTAL PLAIN 



Part of 

KUALA LANGAT DISTRICT 

in 1909 



a.= P.W.D. Lines abandoned 




Scale of Miles 
0123 6 



Emery Walker Ltd. sc. 

FlG. 16. — Map of a Part of Kuala Langat District, showing Spleen Rates in 1909. 



SUMMARY OF EXAMINATIONS 75 

the November examination, her spleen could not be palpitated, 
nor was splenic dullness enlarged to percussion. Of the two 
with enlarged spleen in November, one was a returned bolter, the 
other had suffered from fever on the estate a month previously. 

(1909). — It is sometimes argued that malaria is never as 
severe on flat land as it is on hilly land. This is generally 
so, for the conditions from the first are different. On hill land, 
the coolies are housed on the side of a ravine so that water 
may be conveniently to hand. They are, therefore, placed as 
close as possible to the breeding-places of the malaria carrier, 
that is on the most unhealthy spots on an estate, and there 
they remain. No further opening of the estate alters the 
distance they are from the breeding-place. 

In the case of flat land estates the conditions are entirely 
different. Before a Tamil coolie is brought to an estate, at 
least fifty acres are felled, drained, and burned by Javanese, 
people who are, as we shall see, generally immune to malaria. 

The Tamil on the flat, therefore, starts with the breeding- 
place of the malaria carrier at a distance of some hundreds of 
yards, and every few months further openings put the breeding- 
places farther off. He starts, therefore, under better conditions 
as a rule, and the conditions improve with every additional 
opening. 

That there is no essential difference is seen if a non-immune 
population is placed on undrained flat land. The conditions 
are then the same as on hill land, and the results are the 
same. It is not often, of course, that we see a population under 
such circumstances ; but it occurred at Port Swettenham in 1901, 
and there malaria was as severe as it ever was on any hill estate. 

We have seen, too, that lines close to the jungle have 90 
to 100 per cent, of the children suffering from enlarged spleen, 
and the occurrence of a case of Blackwater fever in a European, 
who lived within 100 yards of the jungle on the flat land, 
supplies a further proof, if the history of Port Swettenham has 
failed to convince. 

Summary of Examination of Children on Flat Land Estates. — 
On the flat land estates altogether 2,295 children were examined 
in 1909. 

Tabulating the results, we find that the health of the lines 
bears a very definite relationship to their distance from the 
jungle, and the following is the table : — 



76 THE MALARIA OF THE COASTAL PLAIN 



Table showing the Spleen Rates of Children living at Different 
Dista?ices from Undrained Jungle on Flat Lands. 





Distance from Jungle. 


Within 
SOO yards. 


300 to 600 
yards. 


600 to 1000 
yards. 


Over 
1000 yards. 


Total. 


Number of Children 

examined . 
Spleen Rates per 

cent. . 


325 

47 


396 

21-9 


532 
II 


1042 
2-6 


2295 
14-2 



It is clear from these figures that malaria can be avoided 
on the flat land by housing coolies about IOOO yards from the 
nearest undrained jungle, and that every yard the coolies are 
removed from jungle improves their health. 

In a later table it will be seen that the death rate of estates 
in Malaya is largely due to malaria, and that were malaria 
abolished the death rate would be about 10 per mille of the 
coolie population as at present constituted. 

Over an area of the Selangor coast, some fifty miles long, 
I have traced how malaria, affecting a population of many 
thousands, has been driven back, year by year, as the land 
has been drained and opened by agricultural operations. 

At the towns of Klang and Port Swettenham, deliberate 
attempts were made to deal with the disease ; and they were 
successful in the highest degree. 

But of infinitely more importance have been the results 
of the agricultural operations. Although malaria may affect 
a town, it is essentially a disease of the country. The capital 
of the peasant is his health, and if this be destroyed by malaria, 
poor, indeed, is he. The planters in Malaya have carried out 
unconsciously it is true, what really form an extensive series, 
of rural anti-malarial and anti-mosquito experiments. I have 
watched, over a number of years now, experiment after experi- 
ment, with control after control, which have proved that the 
pool-breeding anopheline, which carries malaria on the coastal 
plain of Malaya, can be exterminated by open drainage at 
a very low cost ; and that with the extermination of the 
anopheline, malaria has disappeared. Anti-mosquito measures 
have, therefore, been proved on the coast of Malaya to be not 
only entirely suitable to rural districts, but have greatly improved 
the value of the land. 



CHAPTER IX 

THE MALARIA OF MANGROVE SWAMPS AND 
ANOPHELES LUDLOW/ 

"Being in Manila early in 1901," wrote 11 Dr Clara S. Ludlow, 
B.Sc, Ph.D., " it was repeatedly suggested by some of the 
medical officers of the United States army stationed there that 
I should take up the study of mosquitoes, and the thought 
strongly emphasised that the study of mosquitoes was likely 
to be of real benefit to mankind, especially if carried out in 
connection with the occurrence of certain diseases, notably 
malaria." It was a period when the mosquitoes of tropical 
countries were being studied in detail for the first time. Miss 
Ludlow, who had accompanied her brother, a colonel in the 
army, to Manila, was a student of science, well qualified for 
the task ; and the work was regarded as so important that it 
was put under the jurisdiction of the Surgeon-General. Thus 
began a research, which was continued for many years in the 
Philippines, and is still carried on by Dr Ludlow at the Army 
Medical Museum, Washington, where I had the pleasure of 
meeting her in 1913. 

Dr Ludlow soon found that 12 "... the mosquitoes taken 
were not described in the books available, and in a little while 
it became evident that no one knew the mosquitoes of the 
Philippine Islands." She worked, however, in conjunction with 
Mr Theobald of the British Museum, and rapid progress was 
made in describing the species taken. At quite an early date 
(1903) she differentiated the three members of the Rossii Group 
of anopheles, although for many years to follow this interesting 
and important group remained a puzzle to most workers. The 
group consists of three mosquitoes, A. rossii, Giles, A. indefinita 
and A. ludlowi ; the interest lies in the fact that they are so 
much alike that for long many workers did not regard them 
as separate species: the importance, in that only A. ludlowi 
77 



78 THE MALARIA OF MANGROVE SWAMPS 

is an important natural carrier of malaria, while the innocence 
of the other two has been generally accepted. Another point 
of interest is that A. hidlowi breeds mainly along the coast and 
in brackish water. Our knowledge of these mosquitoes has 
come slowly, and even now is probably incomplete. 

Anopheles rossii (type Giles), the first member of the 
group to be recognised, was described by Giles from specimens 
taken in India. It was studied by the Commissioners sent to 
India by the Royal Society ; and their conclusion was that, 
although it could be infected with malaria experimentally, it 
played practically no part in propagating the disease in nature. 
They showed there were wide areas where it existed in which 
the spleen index was low ; if found in malarious places, there 
was also present another anopheles, in which alone malaria 
parasites were to be found. 

Anopheles indefitrita is common in the Malay Peninsula. 
It differs from A. rossii (Giles) in minor details. The evidence 
is against it being a carrier of malaria, for it is regularly found 
in large quantity where the spleen rate is low. Its larvae are 
to be found in small muddy pools and puddles, especially 
when polluted by the presence of animals or man. 

Anopheles ludlowi. — The story has been more involved. 
Dr Ludlow found it to be the species of anopheles most 
frequently taken in the Philippines, and it was associated with 
malaria in such a way as to give her the impression that it 
was an important carrier of malaria — although this was not 
actually proved by dissection. She noted that it was found, 
not only along the coast, but also in inland valleys, far from 
brackish water. 

In Java in 1902 Dr De Vogel 13 found an anopheles 
breeding in salt marshes, often in large numbers in the water 
of sun-cracked mangrove mud. He noted the prevalence of 
this anopheles along the coast, and the existence of high 
spleen rates "60 per cent, to 100 in the native villages 
(kampongs) situated along the coast, and in the two overflow 
canals which carry brackish water far into the land and contain 
innumerable pools between their banks. Among the rice-fields 
and fresh water marshes farther in the interior, the numbers 
vary between 5 per cent, and 25 per cent." Dr De Vogel also 
experimented with this mosquito and was able to infect it 
easily; but he was unable to keep the insects alive long enough 



T3 


o 




cj 


rt 








ifi 




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QJ 


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[To face page 78. 




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Fig. i8a. 




Fig. i8b. 
BKEED1NG-PLACES OF Anopheles ludlowi. 



[To face pagt 78. 



OBSERVATIONS IN JAVA AND THE ANDAMANS 79 

to trace the parasites to the salivary glands. Specimens were 
sent to Mr Theobald, who declared them to be A. rossii, but 
there can be little doubt, in the light of our present knowledge, 
that Dr De Vogel was working really with A. ludlowi. That 
Mr Theobald should have made the mistake shows how close the 
resemblance between A. rossii and A. ludlowi is. To distinguish 
the two is at times difficult indeed ; for in dried specimens the 
leg spots of A. ludlowi may have faded, and in some A. rossii 
there are stripes not unlike spots. Mr R. M. M. Mangkoe- 
winoto 14 has drawn attention to the value of the wing spots 
when the leg markings are doubtful. 

It was not until 1912 that the question was practically 
settled by Christophers 15 in the Andaman Islands, where the 
convict settlement has been notoriously malarious. On investi- 
gation he found that " malaria in the settlement is confined 
to a belt around the margins of the harbour, and is absent 
or nearly so from villages more than half a mile from the 
sea-coast or the salt swamps associated with this. This 
freedom from malaria is seen even in inland villages situated 
on the margins of swamps amidst rice-fields and near 
jungle." 

He ascribed this peculiar distribution of malaria to the 
"distribution of Anopheles ludlozui," and he found malaria 
developing in the stomach wall of two mosquitoes out of fifty- 
three dissected. 

It is of interest that A. umbrosus was not found in the 
Andamans. In 191 3 Dr De Vogel, 16 investigating malaria 
at Sibolga in Sumatra, found it associated with A. ludlowi 
and described how the spleen rate decreases the farther the 
kampong is in from the sea. 

Finally in 1919 Dr N. H. Swellengrebel 17 and others 
published an exhaustive study of the association of A. ludlowi 
with malaria. It is printed in Dutch and English in parallel 
columns, and so is available for those who cannot read it in 
the original. The authors are to be congratulated on their 
investigation, which is a model of what a scientific inquiry should 
be ; and the moderation of their conclusions is altogether 
admirable. It should be read by every student of malaria. 

They found A. ludlowi to be the most important carrier 
of malaria in the parts of Java and Sumatra in which they 
worked. They not only infected it experimentally, but also 



80 THE MALARIA OF MANGROVE SWAMPS 

determined its natural index of infectibility for successive 
months; in each set of observations A. ludlowi is compared 
with other species of anopheles. They compare the malarial 
infection of man and mosquito ; and show that, although A. 
ludlowi is usually confined to the brackish waters of the coast, 
nevertheless it is found in some fish ponds in inland valleys 
in which there is alga; that in mangrove forests regularly 
covered by the tides it does not occur ; while it breeds freely 
in the portions submerged only during spring tides. A picture 
of sun-cracked mud, which is almost a replica of that published 
by De Vogel years before, is given. 

Now Java and Sumatra are volcanic islands, and the con- 
clusions of these authors support the observations originally 
made by Dr Ludlow working in the Philippine Islands — which 
are also volcanic. In the Malay Peninsula, which is not 
volcanic, A. ludlowi has never been found away from the 
coast by either Strickland, Hacker, or myself; and other species 
are responsible for the inland malaria. When visiting Sumatra 
in 1913 I was struck with certain differences between that 
island and the Malay Peninsula; in particular the freedom from 
malaria of some of their opened hill land. These differences, 
and the importance of studying the species of anopheles of a 
country, I discussed with Dr Swellengrebel and Dr Schuffner; 
and it was this discussion, the authors say, which induced them 
to begin their research. The impressions I then gathered have 
been confirmed, and there can be no doubt that important 
differences exist between the two countries, although they are 
separated by only a narrow strait. 

In towns and villages on the sea-coast or mangrove belt of 
the Malay Peninsula which I have examined, malaria produced 
by A. ludlowi alone is rare. A. ludlowi is usually found in 
association with A. umbrosus ; and as good drainage clears 
away the two insects and the malaria produced by them, the 
prevention of malaria has in practice presented little or no 
difficulty in these places. 18 

The mangrove forest consists of a number of species of 
trees which can live only in salt or brackish water ; hence they 
are not found away from the sea-coast or tidal rivers. The 
forest can be divided roughly into two zones : one nearest the 
sea, which is covered twice daily and by every tide ; the other, 
farther inland, covered only by spring tides for a few hours 









Fig. 19A. 




Fig. 19B. 
Breeding-places of Anopheles ludlowi. 



f To face page SO. 



THE MANGROVE ZONES 81 

in perhaps three days of every fortnight. When the forest is 
intact, in other words in virgin mangrove forest, no anopheles 
breed in the outer zone ; and houses built on the sea edge of 
the mangrove have the reputation generally of being free from 
malaria. It is otherwise with the inner zone, even in the 
virgin mangrove. In this inner zone there are, as 1 1S wrote 
in 1903, "vast numbers of breeding-places among mangrove 
trees and stumps. Here crabs raise mounds, and between 
these small pools of water are found. Certain of the pools, 
situated on the zone of land covered by spring tides only, 
become as the result of heavy rain comparatively fresh-water 
pools, and at times I have found these at Port Swettenham to 
be teeming with the larvae of anopheles. This I regard as the 
real danger of a mangrove swamp — and there were large tracts 
of this at Port Swettenham." Two anopheles are found here 
— namely A. umbrosus and A. albotceniatus. 

To put it briefly, the outer zone of the virgin mangrove 
forest is harmless — because no anopheles breed there ; on 
the other hand the inner zone is malarious because A. umbrosus 
and A. albotceniatus live in it ; and the former is a known 
carrier of malaria. As far as I am aware A. ludlowi has never 
been found in virgin mangrove; and, as Strickland has pointed 
out, the larva; appear to require sunshine. 

When man destroys the forest, and more particularly when 
he carries out engineering operations in it, one thing certainly 
happens, he lets sunlight into the land ; another thing may 
happen, he may prevent the tide from covering and flushing 
the outer zone twice a day as it naturally does. A railway 
line along the foreshore is an example of an engineering work 
which might create extensive areas of stagnant brackish water 
in the lower zone. In such pools A. ludlowi may breed in 
enormous numbers ; indeed, I think the largest number of 
larvae of any species ever seen by me in a breeding-place has 
been A. ludlowi; at times they have appeared like a moving 
pellicle. A. ludlowi are to be found, too, in the inner zone 
when the forest has been felled. Yet even in felled mangrove 
the breeding-places of A. ludlowi, albotceniatus, and ludlowi 
are not identical. For while A. ludlowi is to be seen in 
large numbers in stagnant pools or blocked drains free 
from vegetation, the other two will be taken rarely unless 
there is grass, sticks, or some cover ; and they may readily 



82 THE MALARIA OF MANGROVE SWAMPS 

be missed, for they hide themselves away among the black 
roots of the mangrove and can be captured only by scraping 
these with the collecting dish. 

Malaria due to Anopheles ludlowi. — The following is an 
instance of a place in which I found malaria due apparently 
to A. ludlowi unaccompanied by A. umbrosus* It is a coconut 
estate near to the mouth of a large tidal river, and is divided 
into three divisions. The severity of the malaria is indicated 
from the following spleen rates. 

Division I. — Of 5 Javanese children born on the estate, 
4 had enlarged spleens : of 48 Tamil children, 46 (or 95 per 
cent.) had enlargement ; of the other two, one had been on the 
estate four months, and the other one year. 

Division II. — Of 100 children 70 (70 per cent.) had enlarged 
spleen ; and of the 30 others only 1 had been on the estate 
over six months. It is significant that, out of the 100, only 
3 were under two years old. 

Division III. — Twenty-three out of 25 (or 95 per cent.) 
children, who had been on the estate over six months, had 
enlarged spleen. Of 32 under six months on the place — many 
of them only about one month — no fewer than 14 (or 43 per 
cent.) had enlarged spleen. 

A. ludlowi, adult insects, were present in numbers. Im- 
mediately on entering my room, I saw two on my mosquito net. 
In the evening my assistant exposed his arm for about a minute 
in the open air, was promptly attacked, and captured four. 

At daylight on the following morning my assistant searched 
the twenty-six occupied mosquito nets in the hospital, with 
the exception of four which were searched by the dresser ; my 
assistant caught anopheles, the dresser took all mosquitoes 
present. In only two nets anopheles were not found. The 
total catch was 164 mosquitoes, of which 124 were A. ludlowi ; 
the other 40 were Culicines and were almost exclusively Culex 
sitiens, which, like A. ludlowi, breeds in brackish water. 

The estate stretches along the river bank, and is protected 
from tidal flooding by an embankment. At certain times 
the tide gates are opened to admit sea water into the drains, 
so that the nuts may be transported cheaply by floating them 
down the drains. Larvse were found wherever the water 
was stagnant or vegetation existed. In some shallow drains, 

* A. umbrosus has since been found, but is probably not important. 




FlC. 20A. 




Anopheles ludlowi does not breed in these Drains. 



[To face page 82. 




[To face page 82. 



THE CONTROL OF A. LUDLOWI 83 

free from vegetation, crab holes had formed little land-locked 
harbours ; in these larva? were abundant. The larvae were 
particularly abundant where grass, weeds, or small sticks 
were present in a pool or stagnant drain. 

In contrast to these, larvae were not found in the main 
drains where the edges were free from weeds, clean cut 
and deep, and where there was current. 

The Control of A. Ludlowi. — Since Carey Island 
became an estate in 1906 it has been under my care. The 
island is surrounded by large rivers or arms of the sea con- 
taining practically pure salt water. The shores of the island 
were originally covered by the usual Mangrove zone ; and 
as these portions of the land are below high-tide level, the 
whole is protected by bunds and sluice gates. Beyond the 
tidal zone the island is flat alluvial soil like the "coastal 
plain" and contains A. umbrosus. 

The land and general situation of the island is, indeed, 
similar to that of the estate previously described. But whereas 
the estate is and has been intensely malarious, the island 
has been as consistently free from the disease since the first 
year it was opened. And the freedom is due to the following 
simple precautions taken, and the excellent drainage system 
which exists. On the island full advantage has been taken 
of the 16-foot rise and fall of the tide ; and by means of 
low-level tide gates, a system of deep drainage has been 
created far superior to that of the majority of estates on 
the coastal plain of the mainland. 

Opening up was begun at a small clearing in the mangrove 
occupied by Sakais, one of the aboriginal races of the 
Peninsula. When the island was taken over by the company, 
100 acres were reserved for Sakais ; but it was bunded and 
drained by the company ; and, until a part of the estate was 
opened, it formed the company's headquarters. Drainage, 
felling, and clearing of the estate land was pushed on rapidly, 
so that within the first year (1907) 144 acres were planted, and 
within the second year no fewer than 1 828 acres. Each succeed- 
ing year saw an increase in the planted area, until by 1917 
there were some 10,000 acres opened altogether in two estates. 

Now in opening up land, the common, I might almost say, 
the invariable mistake was to house the labour near to jungle, 
either temporarily or permanently. This was never done on 

H 



84 THE MALARIA OF MANGROVE SWAMPS 

the island, the definite policy having been adopted, and 
followed of never housing coolies within half a mile of jungle; 
and the policy has paid handsomely. In 1909 I wrote of 
Estate " EE " :— 

" This estate commenced operations at the end of 1906. 
The labour was at first housed on land originally opened by 
natives, and drains were at once put through a considerable 
area by Javanese. So that when the Tamil labour force was 
introduced later, it was on opened land. The Tamils have 
accordingly never suffered from malaria, and now one of the 
finest labour forces in the country is there, consisting in all 
of about 2000 coolies of whom 1200 are Tamils. 

" The death rate of the estate was 22 per mille in 1908, and 
in 1909 was only 1 1. 

" Owing to the good health of the labour force, over 4000 
acres are now drained and opened, and no set of lines is closer 
than half a mile to the jungle. On 29th December 1909, I 
examined 246 children on this estate, and found only one with 
an enlarged spleen (it was just palpable) giving a percentage 
of 0-4. The boy was in perfect health, and no history of 
malaria was obtainable. The presumption is, therefore, that 
he had malaria when in India. 

" This estate shows that it is not necessarily the oldest 
estate which is the healthiest ; but that old or new the state 
of the health is in relation to the proximity or otherwise of 
the jungle." 

At the time that was written I was not aware that, by the 
draining and bunding, we had escaped danger from A. ludlowi 
in the mangrove zone, as well as the danger from A. umbrosus 
both in the mangrove zone and the more central jungle. Hence 
the reference only to A. umbrosus at that time. 1 

Since 1909 until to-day, the island health has been con- 
sistently good ; indeed, is almost proverbial here. In 1915 on 
one estate, out of 298 children only 13 or 4-3 per cent, had 
enlarged spleen ; and inquiry showed that in almost every case 
the children with enlarged spleens had been previously employed 
on estates known to be malarious. 

Between 1909 and 191 8 the European staff numbered about 
seventeen, of whom only three suffered from malaria. One con- 
tracted his malaria on the mainland, and infected a companion 
living in his bungalow, which was about 400 yards from jungle. 
The other, who lived half a mile from jungle, apparently 




Fig. 22. 
An Automatic Vertical Tidal Gate on Carey Island, designed by Mr C. L. Gjorup. 




■ - 



I 

km 



i - 



"f 



Fig. 23. 
Shows the great depth of Drainage possible by Mr Gjorup's Tide Gate. 

[To face page 84. 




Fig. 24.— A Bund on Carey Island. 




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.— ' 





























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Fig. 25. — An Automatic Flap Tide Valve on Carey Island. 

{To face page 84. 



THE CONTROL OF A. LUDLOWI 85 

contracted the disease on the island. That was in 1912, and 
was the last case in the period referred to. 

The death rates since 1910 have been 21, 86, 26, 15,9, io, 
9-12 and 28 in the influenza year, and 5 in 1919, when the 
average labour force was 2088. The other estate on the island 
has been equally healthy ; the death rates being, since 1912, 
when it was opened, o, 10, 17, 13, 22, 14 and 31 in 1918, and 
7 in 1919. The spleen rate of 120 children examined in 1915 
was i-6 per cent. ; one of the two children with enlarged spleen 
had worked on an estate in Perak, the other in Malacca. 

The good health of two estates on the island stand in 
striking contrast to the malarious coconut estate previously 
described ; and shows how completely the malaria of both the 
mangrove swamp and coastal plain can be controlled by good 
drainage, and the selection of good sites. 

I could give other instances of estates situated on the sea, 
and within the reach of brackish water, where A. ludlowi and 
its malaria have been controlled. In a later chapter, however, 
I shall trace the recrudescence of malaria in once healthy places 
on the reappearance of A. ludlowi when breeding-places suitable 
for it have been created. They throw light on the mosquito 
and malaria from a somewhat different aspect : yet serve to 
confirm the conclusions already reached. (See Chapter XXII.) 



CHAPTER X 

THE COASTAL HILLS 

The Persistence of Malaria in Certain Rural Areas. (1920). — In 
this chapter I deal with an area of hill land which is malarious 
when under jungle, or when the ravine streams are choked by 
weeds after the jungle has been felled. It is equally unhealthy 
when the jungle has been felled and the ravine streams are 
free from weeds, for a new malaria carrier appears, namely, 
A. maculatus. The conclusions reached ten years ago have 
been confirmed, and much additional evidence could be ad- 
duced were it necessary to do so. It will be sufficient, 
however, if I reproduce what was written in 1909, practically 
the only alteration being that Nyssorhynchus willmori now 
appears as A. maculatus. 

(1909). — In the previous chapters I have shown how malaria 
has disappeared from certain portions of the coast districts of 
Malaya, as the land has been drained, and the jungle felled. 
That this often occurs is well known to all with tropical experi- 
ence ; and it is with the hope that this will occur that the pioneer 
battles with his troubles. The hope is so strongly implanted that 
he takes it as a matter of course that the health will improve 
as the land is opened up. 

We often hear of what a terrible place some spot was or is. 
We rarely hear that a place was abandoned on account of its 
ill-health. But we never seem to hear that a place always 
remains unhealthy, and never improves as time goes on. This 
is because after a time the population of an unhealthy place 
consists almost entirely of those who have acquired a certain 
amount of immunity. New people have practically ceased to 
come to it. And so the health seems to improve, and local 
experience seems to fall into line with the general experience 

86 




[To face 'page i 



ANOPHELES MACULATUS 87 

of the tropics. Yet it only wants new arrivals to come in 
numbers to start a severe outbreak of malaria. I have now, 
however, to record that in certain portions of the district, there 
has not been the slightest improvement in the six years during 
which they have been under my observation, nor have I any 
reason to suppose they will improve as long as the present 
conditions favouring the mosquito persist. The land to which 
I refer is the hilly land of the coast districts of Selangor, in the 
ravines of which run streams of water, often of very small size 
indeed. In this hill land the mosquitoes which are to be found 
are A. umbrosus as in the flat land, A. maculatus and A. karwari. 
Now the important point about these mosquitoes is that, if 
a ravine stream be kept free from grass and other weeds, 
A. karwari and A. timbrosus no longer breed in it, while 
A. maculatus will breed in streams which have been absolutely 
free from grass and weeds for three years to my knowledge. 
Extensive observation has shown that it is not in all ravines that 
A. maculatus can be found, nor is it always present in the same 
ravine. It is possible there may be some seasonal variation,* 
but of this I am not yet warranted in making any definite 
statement. I can say, however, that no amount of weeding or 
other care of a mountain stream will abolish A. maculatus, 
which I have found to be a natural carrier of malaria. 

For some years malaria has formed a subject of anxiety to 
the managers of certain estates in the district, since their 
labour forces have been seriously crippled, apart from the fact 
that the Europeans have also suffered severely, and Blackwater 
fever has occurred in one instance. It was always hoped that 
the general experience would hold good in these estates, 
and that, as they were more opened up, the health would 
improve. In the meantime there was nothing to do but to 
push on with the opening programme, and give quinine to the 
coolies systematically. This has been done, thereby reducing 
the death rate and improving the general health of the coolies. 
The arrival of any considerable number of new coolies was, 
however, always the signal for an outbreak of the disease, and 
the older coolies who were apparently becoming acclimatised 
appeared occasionally to suffer with the new ones. 

In the middle of 1907, when my investigations on the 
estates had for certain reasons suffered interruption, the 
* See the maculatus wave, Chapter XXVIII. 



88 THE COASTAL HILLS 

position was as follows. I had determined the percentage of 
infected children on many of the estates of the district. I had 
also determined the adult mosquitoes to be found in the coolie 
lines, and made certain observations on their breeding-places. 
I had determined that the carrier of malaria on the hill land 
was A. maculatus, and that it was confined exclusively to the 
hill land. I had also observed on three estates that it was 
present when there was grass and other weeds in the drains, 
but not when these drains were clean. I attributed their 
absence to the freedom from weeds. I had also determined 
its absence from certain ravines altogether. I, therefore, con- 
cluded that when further opening had taken place, the health 
of the labour would improve on the hill land places, as it had 
already done on the flat land places to my knowledge. 

In 1908 I was on leave in England, and on my return to 
Malaya was for several months fully occupied in administrative 
details of the hospital system, which I was organising, for the 
estates. During this period I came to the conclusion from 
what I incidentally saw, that despite the lapse of two years 
and despite the greater areas opened, no improvement had 
taken place in the hill land estates. 

I accordingly determined to investigate the matter de novo. 
I determined to examine every set of coolie lines in the 
district and particularly those on the hill land, with the object 
of ascertaining the exact condition of each. I also decided 
to make a fuller inquiry into the breeding-places and habits 
of the anophelines. The result of this inquiry has been to 
show that A. maculatus cannot be exterminated as long as 
there is water in the ravines in which it can breed ; secondly, 
that malaria is as prevalent in the hill land as before ; and 
thirdly, that quinine in the therapeutic doses can hold in check, 
but cannot eradicate, malaria. 

It will be unnecessary to enter into details of each of the 
hill land estates, but the following figures will show the general 
condition. 

Estate " RR." — This is a large estate, work on which was 
begun in 1906. From the first, malaria has been prevalent. 
Quinine was begun in. 1906 in doses of ten grains twice a week ; 
but as this was apparently without effect, it was increased to 
ten grains daily with double doses to those who did not work. 
The following table shows the condition : — 




fro , 



! page 88. 



HILL LAND ESTATES 



89 





1906. 


1907. 


1908. 


1909. 


Blood examination — 
Number examined . 
Per cent, infected 

Spleen — 

Number examined . 
Per cent, enlarged 
Death rate 


61 

73 

6i 
65 


43 
S3 
73 


i6s 


174 
49-8 

43 



It should be mentioned that one set of the most unhealthy 
lines was abandoned in 1908. During 1908 the amount of 
quinine administered was much less than had been the case 
in 1907, as ankylostomiasis was said to be the real cause of 
death in many of the coolies that year. This led to the 
necessity for giving quinine being questioned, and on my 
return from leave I found an entirely insufficient quantity was 
being given. The dose was at once increased and the result 
has been to reduce the sickness and the death rate as is seen 
from the above table. 

From the tables on p. 92 it will be seen that the death 
rate in 1908 was generally higher than in the previous year. 
There was no special immigration in 1908; indeed it was 
smaller than usual ; and I attribute it to the idea spread about 
that ankylostomiasis was the chief cause of the death rate. 
Quinine was consequently neglected on some estates. 

The coolies on Division I. of Estate " RR " are housed in 
three places. The health of these varies, at least the spleen 
rate varies, being 90-9 per cent, in one place, 766 in another, 
and 36-6 about a quarter of a mile from the worst. The 
majority of the coolies are now living near the last of the three 
places — hence the lower spleen rate for 1909. It is possible 
the mosquitoes infecting the place with the low spleen rate, 
come from a ravine near to the place with the highest. The 
point is one of the greatest practical importance, but I have 
not yet finally determined it. In addition there has been a 
considerable number of new coolies lately to this division, so 
the spleen rate is lower than it will be when the recent 
immigrants have had time to become infected. 

The number examined on the other two divisions on this 
estate were as follows : — 



90 



THE COASTAL HILLS 



No. 

Examined. 


With Enlarged 
Spleens. 




Per Cent. 


63 


79-3 


33 


757 



No. II. Division 
„ III. Division 

An idea of the amount of malaria present will be gathered 
from the fact that of thirteen children on the estate only two 
and a half months, no fewer than eight had splenic enlargement. 

The death rate of this estate will be referred to later when I 
deal with the effect of quinine. 

Estate " SS." — This estate is on the border of the hilly land, 
and its coolie lines are situated on the end of a ridge. The 
number of children examined was thirteen and the spleen rate 
307. Five of these children had been only one month on the 
estate, so the corrected rate would be fifty. 

Estate "TT." — This estate lies on the edge of the hills with 
part on the hills and part on the flat. The lines at the west 
end are close to jungle now being opened and on the flat ; the 
central lines are on the flat about half a mile from the nearest 
jungle ; while the east lines are among the ravines, but ravines 
which are clean. Anopheline larvae were found only a quarter of 
a mile from these lines in a clean ravine. No larvae were found 
in two ravines close to them. Sinniah's lines are about a quarter 
of a mile from rather poorly drained native holdings. 

The summary of this estate is then : — 



Year. 


West Lines. 


Central Lines. 


East Lines. 


Sinniah's 


jines. 


No. 

Examined. 


Spleen 
Rates. 


No. 
Examined. 


Spleen 
Rates. 


No. 
Examined. 


Spleen 
Rates. 


No. 
Examined. 


Spleen 
Rates. 


1906 
1909 


14 
49 


64 
51 


28 
47 


32 
17 


5 
31 


57 
45 


17 
S 


35 
37 



I should say the east lines of 1909 were on the same range 
of hills, but not on the same spot, as those of 1906, which had 
to be abandoned on account of their ill-health. 

The figures are, therefore, not comparable as expressing the 

condition of health of the identical places, as the other figures 

■ do throughout the book. The figures, however, show that this 

estate is in much the same condition as it was. The central 

line spleen rate of 1909 was affected by four new arrivals from 



WHAT IS A HILL? 



91 



an estate whose spleen rate is about 50, otherwise it would have 
been 9-3, which would be in agreement with the rate generally 
found for the distance the lines are from a breeding-place of 
anophelines. 

Table showing Spleen Rates and Death Rates of Estate " TT." 





1900. 


1007. 


1 
190S 1000. 


Number examined 
Spleen rate 
Death rate . 


67 

41-7 

48 


86 


135 
37 
64 



From the figures on p. 92 it will be seen that on the other 
estates in the hilly land there has been no improvement in 
the amount of malaria, as indicated in the spleen rate during 
the years I have been observing them. The death rate 
has varied, but this, as I shall show, has been due to quinine 
administration. 

These figures show in the most unmistakable way that there 
has been no improvement in the health of these estates. They 
indeed only confirm what I had already observed from the 
hospitals, from visiting the estates, and from the health of 
the Europeans. 

What is a Hill?— On one occasion I visited Lanadron 
Estate. On the flat river bank the spleen rate was low and 
the children were healthy. Further in, at the " Darat Lines," 
no fewer than 17 out of 27 children (62 per cent.) born on the 
estate had enlarged spleen. The "Darat" is about 23 feet 
above the general level of the surrounding flat land, and might 
have been, at one time, a sand bank in the sea. Yet in the 
eyes of A.maculatus it has found favour, and to them, at least, 
it is a hill. At the time of my visit I searched for them in 
vain, but Dr Rattray afterwards found them in abundance. 



[Table. 



Details of Hill Land Estates. 





1904. 


1906. 


1906. 


1907. 


1908. 


1909 


Estate. 
Blood— 

Number examined 
Per cent, infected . 






12 
83-3 








Spleen — 

Number examined 
Per cent, enlarged 
Death rate . 






12 
100 


18 

77-7 
60 


300 


13 
100 


Estate. 
Blood— 

Number examined 
Per cent, infected 


41 
37-S 


40 
12-5 










Spleen — 

Number examined 
Per cent, enlarged 
Death rate . 




40 

17-5 


43 
3° 
95 


138 


176 


49 

55 


Estate. 
Blood— 

Number examined 
Per cent, infected 


6 

100 


17 
n-7 


18 
94 








Spleen — 

Number examined 
Spleen rate per cent. 
Death rate . 








200 




42 
83 


Estate. 
Blood— 

Number examined 
Per cent, infected 


6 

100 


17 
23 


26 
96 








Spleen — 

Number examined 
Spleen rate per cent. 
Death rate . 






26 

80 

300 


178 




13 
100 


Estate. 

Spleen — 

Number examined 
Spleen rate per cent. 
Death rate . 






13 
100 
150 


56 


223 


15 
100 


Estate. 

Spleen — 

Number examined 
Spleen rate per cent. 
Death rate . 






14 
71 


60 


90 


20 
95 


Estate. 
Spleen — 

Number examined 
Spleen rate per cent. . 
Death rate . 


... 




18 
100 


6 


I 

58 


29 
100 


Estate. 

Spleen — 

Number examined 
Spleen rate per cent. 
Death rate . 






260 


93 


250 


15 
100 



CHAPTER XI 

THE EFFECTS OF MALARIA 

(1920). — The time was towards the end of July last year: 
Scene, the hill above Minehead in the county of Somerset : 
Dramatis personce, the author and his two youngest sons on 
horseback. The school term had ended the day before ; this 
was the start of our long-talked-of riding tour on Exmoor. 
The sky indicated perfect weather; it was one of the glorious 
mornings that England sometimes vouchsafes her long-suffering 
people. Below was the Bristol Channel ; across it were the 
Welsh hills. Dunkery looked down on us from the south. 
The Metropole Stables had mounted us excellently, and as 
we settled into our saddles for the 20 -mile ride through 
Selworthy, Porlock Weir, and Ashley Coombe to Lynton, we 
talked of many things — but not of malaria. That was a thing 
forgotten. We were living a life where it played no part. 
Ten thousand miles away was the Malay Peninsula, its fever 
and its jungle. The purple heather was under us, the horses 
were keen, and away we went. 

And as we travelled we fell into conversation with a 
gentleman trying a hunter. Inadvertently I used the word 
" syce." As a touch to a secret spring, or the " open sesame " 
of the immortal tale, the doors of the East rolled open, and 
we talked of far-off lands. Although long retired from business, 
he had lived in Calcutta for many years, and he still had 
interests in the Malay Peninsula. One estate, to which he 
referred, I knew by repute as very malarious, although I had 
never been there ; so I asked him about it, without indicating 
my profession. And he replied that it was just like so many 
other tropical ventures : " You start in gaily expecting great 
gain ; but somehow fever strikes it in the first year, and before 
you know where you are, you have spent double the estimate." 
93 



94 THE EFFECTS OF MALARIA 

A true saying, as we shall see from what I wrote ten years 
ago ; nor need I add to it. 

(1909). Effect of Malaria on the Europeans. — During the 
years I have known this district, I am talking now of hill land, 
only two Europeans have been known to escape the disease. 
They lived on a spot where the spleen rate is only 20. It 
is the place which is farthest from the breeding-place of 
anophelines, being on a point well away from any ravine or 
jungle. That such a spot should be found so near to very 
unhealthy places is of the most hopeful augury, showing that 
.the flight of the hill-land mosquito is by no means great. 

There are at the present moment twenty-nine Europeans 
living on ten hilly land estates. Of these twenty-five have 
had malaria at some time or other. Of the four who have 
not had the disease, two have been less than one month 
on the estate; one takes 15 grains of quinine daily; one has 
been six months on the estate without getting the disease. 

As I write I have a record of the Europeans who have been 
on these estates during the past four years. It shows how 
practically all have had the disease, how from time to time they 
were invalided either to hospital, or off on sea-trips to recover 
their health, or to Europe on long leave. It shows how many 
have left the estate permanently, unable to withstand the 
disease. One man who had suffered severely from malaria 
had Blackwater fever, but fortunately recovered. There is 
only one bright spot in the record ; it is, that no European 
has died from malaria. 

So much sickness among the Europeans means that they 
cannot supervise their work properly ; and if there be much 
sickness among the labour force at the same time, the absence 
of the controlling and directing force of the estate is, indeed, 
deplorable. Few native subordinates can be trusted to see that 
quinine is properly administered to a labour force, and one 
of the great troubles is that, if the manager from sickness 
cannot supervise it, the subordinate is very liable to do this 
duty in a perfunctory way. The welfare not only of the 
estate, but of the labour force, depends, therefore, on the well- 
being of the manager. 

Effect of Malaria on the Coolies. — No less severely has 
malaria affected the coolies. In visiting estates I have 
always noted all cases of sickness seen in the coolie lines ; 



EFFECT OF MALARIA ON THE COOLIES 95 

in addition I have noted on the opposite page of my book 
any general observations which might seem of importance- 
I have, therefore, a fairly complete record for some years 
of the health of the estates which have been under my care. 
From this book I will give the substance of a few notes 
showing the effect of malaria. 

On one estate 170 coolies were recruited. They refused 
to take quinine at first, and were a somewhat unruly gang. 
Within two months of their arrival I visited the estate and 
found that on the day of my visit 102 out of the 170 were unfit 
for work. Many of these were removed to hospital. A month 
later I note, "Of the gang of 170 only 57 remain on the 
estate. Of these 29 working, and 28 off work." Practically 
all these coolies were lost to the estate. 

Of another estate : " Have been having a bad time with 
malaria — turning out 170 out of 340 coolies." The following 
month turning out 179 out of 250 coolies. The following 
month again, the note is " 150 coolies." In other words 
the coolies had either given notice and left or absconded. 
On this estate the labour force was reduced in three months 
from 340 to 150. I need hardly say that weeds got a firm 
hold of it. 

Another estate: " Have been very bad with fever, practically 
every coolie had it, and about six deaths. Appear to be 
getting it in hand with quinine. 140 coolies working out 
of 350." The following month, "turn-out 150. Coolies looking 
better." A month later the manager remarked, " turn-out 
somewhat better but accounts not made up." The manager 
had been very ill. He was taking infinite pains with quinine 
administration. He had every room in his lines numbered 
and the name of every coolie who lived in each of these 
rooms, in a special book. 

He tried to get every coolie twice daily, and ticked off 
in his book when each coolie had received his quinine. 
Only those, who, from visiting coolie lines, know how difficult 
it is to account for each coolie on an estate can estimate 
how much labour this meant. 

Another estate : " 19 cases of malarial dysentery. The 
manager had not given quinine when complaint was dysentery. 
Every one gave a history of fever five to ten days previously. 
Are getting a considerable amount of quinine. Seventy-five 



96 THE EFFECTS OF MALARIA 

out of 190 working. A month later I note, " Now only about 

80 coolies on the estate. Others wish to leave, but 

and and persuaded them to stay for two months. 

Many have died in hospital." I promised that if they would 
take their quinine regularly and would report at once to the 
manager when ill they would not die. New lines were also 
built for them in another place. A month later I find less 
fever on the estate, and note, " old lines abandoned, coolies 
healthier." 

Among the children malaria is no less severe. On 
one occasion I was asked by a manager to advise him 
what could be done for the children, as 15 children had 
died in the previous two months out of a total of 33. He 
told me a native clerk was giving them quinine daily. 
I examined the blood of the remaining 18 and found 
parasites in 17 of them. Such a terrible death rate among 
the children affects the mothers of the estates and leads to 
loss of labour, since the coolies naturally refuse to live in 
such unhealthy estates. 

I have been struck by the small birth rate of malarious 
estates, including those on which quinine is given. I have had 
no opportunity of investigating this, but inquiries are now 
being prosecuted. It has been said that quinine may have 
some injurious effect in reducing the birth rate. I am unable 
to express any opinion on the matter. 

I am indebted to the late Mr E. V. Carey for the 
following :■ — 

Notes of Fever experienced upon New Amherst Estate. 

"Between the years 1892 and 1898 there were on an 
average over 50 Tamil women upon the check-roll each 
year. Yet in the whole period no living child was born. 
Several women became pregnant, but only in one case 
did the child become quick, and even in this case the woman 
eventually had a miscarriage. The estate was so riddled 
with malaria that the coolies were all miserably anaemic 
and lacking in strength. So anxious was the management 
that the stigma attached to the absence of child-birth should 
be removed, that every possible care was taken of the women 
when they became pregnant; light but regular work being 
provided for them, and a supply of milk, etc., being given 
them ; but all with no result, although a big present was 
offered to the woman who first brought forth a living child, and 



NONIMMUNE COOLIES 97 

the coolies were all most anxious themselves that this reproach 
should be removed. 

"The supply of cooked rations to all coolies under the 
supervision of a high caste cook worked wonders in improved 
health and general physique, but when the coolie insisted 
in returning to the system of feeding himself there was soon 
a relapse, and the estate had eventually to be abandoned. 
During the last two years, at least, all coolies were given 
a 5-g ram pill of quinine each morning at muster, together 
with a cup of hot coffee." 

This is very striking evidence of the effect of malaria 
on the birth rate, of the practical inutility of small doses 
of quinine in intensely malarious spots, and of the difficulty, 
indeed impossibility, of carrying out the most beneficent 
measure in the face of native opposition and prejudice. 

The effect of the introduction of any large number of 
new coolies to estates of such an unhealthy character, as 
those I am describing, can be estimated from the following 
extract from my annual report for 1906, quoted in the Selangor 
Administration Report for the same year. 

" The great increase in the death rate has been due to the 
introduction of a very large body of Tamil coolies, and the 
spread among these of malaria, mostly of the malignant type. 
These coolies came mainly from famine districts in India, and 
while of a fair average physique for recruits, naturally do 
not compare in their capacity of resistance to disease with 
coolies who have been well-fed and well-housed for a year on 
the estates here. Among these coolies malaria spreads with 
extraordinary rapidity, and the systematic doses of quinine, 
which were sufficient to maintain the older coolies in health, 
appeared to have little effect on these. Within two months, 
it is hardly an exaggeration to say that 90 per cent, of these 
coolies in the Batu Tiga district were infected with the 
disease; and the children suffered with 1 equal or greater 
severity. From the new it spread to the old coolies, and 
also to the Chinese and others working on the estates draining 
and building lines. Among the Chinese, who will not take 
quinine, it was very fatal, and many of them were brought 
to the hospital in a moribund condition. The new coolies 
literally made no stand against the disease, and on some 
estates there was difficulty at first in inducing them to take 
quinine. Another fruitful cause of death was the bowel 
trouble, which so frequently supervenes on an attack of malaria. 
In the hospital in the month of December, out of forty-seven 



98 THE EFFECTS OF MALARIA 

deaths due to malaria, no less than thirty-four were the result 
of bowel complications. These patients rarely complain of 
fever ; and it is only by microscopic examination of the blood 
that the malaria element in the case is detected. At first 
the necessity of giving quinine in addition to other treatment 
was not recognised on estates, as the coolie made no complaint 
of fever, and the consequence was that many new coolies, with 
no stamina to spare, so to speak, were literally past hope in 
three or four days. As I had occasion to point out a year or 
two ago in a paper on quartan malaria, patients with dropsical 
swelling resulting from malaria are often unaware they have 
malaria, even when the thermometer shows they have a 
temperature of 102° F., and their blood is swarming with 
parasites. As if further to confuse the issue, many of the 
new coolies rapidly became anaemic and dropsical from the 
malaria, and attributed their illness to everything but the right 
thing. In some cases malignant malaria was worthy its name, 
and struck dead those who forty hours before had been 
at work. It ultimately became obvious that the only way 
to save the coolies was by daily administration of quinine 
to every coolie on the estate. This is now being done on eight 
estates with an aggregate labour force of about 2000 coolies, 
and fortunately there is some evidence that the coolies begin to 
appreciate the value of the drug, at least there is now no 
opposition to its administration. " * 

Variation of Death Rate with Spleen Rate. — The important 
influence which malaria has on the health of an estate will be 
more easily realised from a study of the relationship existing 
between the spleen rate of the estates obtained from my 
examination of the children and the death rates taken from 
the Indian Immigration Report for 1908. 

The table on p. 99 shows the death rates of the estates 
arranged in accordance with their spleen rates. It shows the 
total population living on estates where the spleen rates varied 
from o to 100 per cent, the total number of deaths in, and the 
death rates of, these populations. 

These figures exhibit the terrible effects of malaria, and 
I have exhibited them in graphic form in the chart on p. 100. 

* Next to the anopheline the introduction of a large body of non- 
immune coolies is the important factor in the production of the severest 
outbreaks of malaria in the tropics. Captain Christophers and Dr 
Bentley have called the condition produced Hyper-endemicity, in a 
valuable paper on "The Human Factor in Malaria." 19 This is truly so 
called since the number of non-immune persons is greater than ever occurs 
in a normal population. 



DEATH RATE AND SPLEEN RATE VARIATIONS 99 



Spleen Rate. 


Average 


Number of 


Death Rate 


Population. 


Deaths. 


per 1000. 


o to IO 


7106 


175 


24-6 


IO ,, 20 


492 


18 


36-0 


20 „ 30 


2291 


143 


62-4 


30 „ 40 


II2I 


90 


82-0 


4° 11 5° 


65 


2 


30-0 


50 „ 60 


767 


35 


45-6 


60 „ 70 


1738 


232 


133-4 


70 „ 80 


H65 


189 


162-2 


80 „ go 


180 


6 


34-o 


90 ,, 100 


933 


163 


i67-5 



From o to 40 the influence of malaria is unaffected by 
systematic quinine administration, except in the case of one 
estate, " S." From that onwards it is given with varying 
degrees of thoroughness. I think it not improbable that, 
although it has been possible to plot the lower values as a 
straight line, that from the point at which quinine begins to 
influence them, the values, if uninfluenced by the drug, would 
be represented by a curve rising to about 300 per mille. It is 
difficult to believe that the considerable doses of quinine given 
to a population of 1165 on the estates in the group 70 to 80 
should have had no effect. The death rate of several estates, 
whose spleen rate is between 90 and 100, ranges between 200 
and 300 per mille. 

As will be seen from the wastage chart on p. 101, the greater 
the amount of malaria the greater the wastage from all causes. 
To maintain labour forces on the more unhealthy estates at a 
constant strength, larger proportions of the coolies would be new ; 
and the death rate of these would be higher than that of the 
older coolies. Among the more unhealthy estates there would 
thus be death rates increasing at an ever-accelerating rate. I 
do not think 300 per mille would be the maximum in a locality 
of the most intense malaria were the labour non-immune. 

The values which are plotted below the straight line are 
known definitely to be the result of quinine to a great extent. 
Between 40 and 50 the low death rate is due to all the coolies 
(65 in number) on one estate having been dosed daily with 
10 grains of quinine, and once a week with castor oil. The 
low death rate on the estates, whose spleen rate was between 
50 and 60, was due to two of the estates using quinine, one in 
the most thorough manner possible. The same applies to the 
low death rate with the spleen rate from 80 to 90. 



100 



THE EFFECTS OF MALARIA 



Death rate per WOO 




FlG. 28. — Chart showing Variation of Death Rates of 1908 and 1909, 
with Spleen Rate of 1909. 



SHOWING WASTAGE RATE WITH SPLEEN RATE 101 

The plotting of the death rate values shows in a graphic 
manner not only how malaria is responsible for most of the 
deaths on the estates, but enables us by exterpolation to arrive 
at the conclusion that were malaria eliminated the death rate of 



Rate per cent of Coolie wastage above normal this being taken as average 
of all estates with spleen rate below ten per cent. 



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Fig. 29. — Chart showing Wastage Rate of 1908 with Spleen Rate of 1909. 



102 THE EFFECTS OF MALARIA 

the Tamil population on an estate would be about 15 per mille. 
[1919. — We now know it would be under 10 per mille. — M. W.] 
The line shows, too, how money can be spent with most profit 
and advantage in improving health on a malarious estate. 

The sum of money which would be required to reduce the 
deaths from causes other than malaria by 3 per mille would 
in all probability reduce the deaths from malaria by 100 per 
mille, if spent on anti-malaria works. It is absurd to talk of 
applying to malarious estates the sanitary measures which are 
required in an overcrowded town, and expect them to improve 
its health. Expenditure on such measures would only be an 
obstacle to expenditure on the special sanitation required by 
the local conditions. As will be seen later, sanitary areas free 
from anophelines should be established on malarious estates, 
and the coolies housed on those areas. 

The Death Rate uninfluenced by Quinine. — (A) Public Works. 
Those who have seen the terrible death rate on public works 
in the Federated Malay States, such as the Ampang and Ulu 
Gombak Water Works of Kuala Lumpur, the Ayer Kuning 
Water Works of Klang, the Changkat Jong Water Works of 
Teluk Anson, the Ayer Kuning railway tunnel near Taiping, 
will readily believe, I think, that a death rate of 300 per mille 
is no exaggeration. As Daniels says, " Under such circum- 
stances in Malaya, malaria is as severe and prevalent as in bad 
parts of Africa.' - 

(B) Estates. From what I have seen on the estates under 
my care, and from what I have gathered when travelling through 
the Federated Malay States, I have come to the conclusion 
that malaria is the chief factor in the death rate of estates. 
It is entirely in keeping with the observations I have made, 
that of twenty-one places of employment, whose death rate was 
over 200 per mille as given in the Indian Immigration Report 
for 1908, no fewer than eighteen of these should be estates in 
hill land, and of the three exceptions, two were estates whose 
coolie lines were close to jungle. I have no information as 
to the third. [1919. — I have since been informed the third 
estate suffered from a bad water-supply. — M. W.] 

The average labour force employed on these places was 
2130, and the average death rate was 280 per mille. On some 
of these places quinine was certainly given, though probably 
not very thoroughly ; but on the majority I believe it was 



DEATH RATE UNINFLUENCED BY QUININE 103 

not given systematically to the whole labour force. Cholera, 
plague, and smallpox were not present to swell the death rates. 
(C) India. Perhaps to those not acquainted with what 
malaria can do, the following extracts from the Proceedings of 
the Imperial Malaria Conference held at Simla in 1909 will give 
some idea of how great an effect this disease may have on the 
death rate : — 

" During the two months of October and November the 
number of deaths recorded in the Punjab as due to fever was 
307,316, as against less than 70,000 in both 1904 and 1905, 
and less than 100,000 in 1907. 

"Studied in more detail, the ravages of the epidemic in these 
areas where it was most intense are more apparent. In Amritsar 
the mortality for many weeks was at the rate of over 200 per 
mille. In Palwal the mortality rose to 420 per mille, and in 
Bhera to 493 per mille. Curiously in Delhi, a notoriously 
malarious town, the death rate rose to only 149 per mille. 
But a closer examination of the statistics shows that parts 
of this town were much more seriously affected than one would 
judge to be the case from the statistics of the whole city ; 
in Ward I., for example, the mortality rose to over 300 per 
mille. 

" The death returns of Amritsar show that the densely 
crowded outer portions of the city were mainly affected. 
Again, in these the mortality was higher than the figures for 
the whole city would indicate. In Division IX., for example, 
with a population of 17,206, the death rate rose to 534 per 
mille, and for six weeks was over 400 per mille. 

" In the district returns, with the exception of those relating 
to the Gurgaon district, which show among a population of 
687,199 a death rate of 267 per mille, the mortality rates 
are not so high as those given for the towns. This might 
be taken as showing that the mortality was greater in towns 
than in rural areas, but a study of returns from individual 
thanas and villages modifies this conclusion, both thanas and 
villages frequently showing mortality rates during October and 
November of 300, 400, or even 500 per mille." 

I think, therefore, that the curve of the death rate un- 
influenced by quinine as I chart it, is a close approximation 
to the truth. It is based on the maxima of the death rates 
and is certainly no exaggeration. 

Wastage of a Labour Force. — Although local factors have 
a powerful influence on the happiness and welfare of a labour 



104 THE EFFECTS OF MALARIA 

force, it can easily be understood that where an estate is 
unhealthy, coolies will be less contented and will be less inclined 
to stay. A month's notice frees a coolie on the estates of 
Selangor, and in many instances he leaves without giving 
even the legal notice. There is no indentured labour. 

The chart (p. 101) illustrates how on the estates under 
my care the wastage of labour from all causes has a very 
definite relationship to the health, as exhibited by the spleen 
rate. 

I have taken, as the base line, the wastage on the estates 
having the lowest spleen rate ; and the other wastages have 
been calculated as a percentage above or below this. The 
chart shows that the greater the spleen rate the greater the 
loss of labour. There are only two exceptions. The very 
great loss on estates whose spleen rate was from 20 to 30 
was due to practically the whole of the coolies on one estate 
leaving, owing to the conduct of a drunken mandor. The 
Government Immigration Report deals with this. Great loss 
was due on another estate to differences between the coolies 
and the manager. These are exceptional circumstances, and 
this group of estates showed a wastage in 1907 quite in line 
with that of other estates. 

On the group of estates, whose spleen rate was 90 to 100, 
the actual loss was 507 per mille. In other words, while the 
coolies remain on an average three years on the healthiest 
estates, they remain only two years on the most unhealthy 
estates. The extra year means, for the healthy estates, an 
increase of the labour force by 50 per cent., and more than 
a 50 per cent, increase in the work done ; for the coolie at the 
end of his two years is a skilled workman, especially where 
he is tapping. Malaria is, therefore, an economic factor of 
great importance. 

Economic Effects of Malaria on the Estate. — In the working 
of an estate, a certain number of coolies are required for each 
class of work, and the manager must estimate some months 
before how many he will require, so that the necessary number 
may be recruited from India in time for the work. Any 
extension of the estate necessitates more coolies. One of 
the most important works of an estate is weeding. In a 
tropical country like this weeds grow with surprising rapidity ; 
in less than two months they will form in many places a 




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[To face -page 104. 



ECONOMIC EFFECTS OF MALARIA 105 

complete cover to the ground, and having seeded, it will take 
months to eradicate them. In addition, a grass called lalang 
often takes root, as its seeds are blown to great distances by the 
wind. The roots of this grass grow several feet deep, and to 
eradicate it costs $50 an acre at least. 

The most economical method of working an estate is to 
have a labour force of such strength that the whole estate can 
be weeded once in from two to three weeks. Not a weed then 
has time to seed, and the cost of weeding falls to about 50 to 
60 cents an acre. 

If, then, there are too many coolies on an estate, the work 
will be insufficient for them, which will lead to dissatisfaction ; 
while, if there are not sufficient coolies, the work gets behind, 
and if this work be weeding, then the whole estate may be 
covered with lalang. As the cost of bringing an acre of rubber 
into bearing is generally estimated at about $250, it will be 
seen that the effect of an outbreak of malaria, which seriously 
cripples a labour force even for only a few months, may easily 
increase the original cost of an estate by 20 per cent., and 
on an estate of 1000 acres will actually cost about ^6000 
sterling. 

(1920). — The foregoing was written at a time when the 
estates were being developed, and the chief problem was to 
prevent them being overgrown by weeds and ultimately 
smothered by the jungle. 

Later, when the heavy shade of the rubber trees removed 
anxiety on that score, the shortage of labour made it difficult 
to tap the trees and collect the rubber. Indian labour being 
unequal to the task, Chinese labour at a much higher rate of 
pay had to be employed. How much extra the cost was will be 
found at the end of Chapter XV. on Seafield Estate. 



CHAPTER XII 



ON QUININE 



Value of Quinine Administration. — During these years it must 
not be thought that nothing was being attempted to eradicate 
the disease. About 1902 I had arrived at the conclusion that 
once a man was infected with malaria, he should take quinine 
after his apparent recovery daily and not once a week, as was 
the custom. I made this observation first of all from one of 
my dressers (Lewis) in Klang Hospital, who, although he took 
quinine once a week with a tonic in the interval after the 
pyrexia had disappeared, had a return of the pyrexia about 
every ten days for many weeks, and only got rid of it finally 
by constantly taking quinine for some months. 

In 1904, having determined that there was much malaria on 
certain estates, I advised the administration of quinine at first 
in weekly doses of 10 grains, and later of bi-weekly doses.* 

The following tables show the result of giving quinine in 
the above-mentioned doses. 

Table showing the Numbers of Children infected with Malaria in the 
months of November and December on certain Estates. 



Estate 
Number. 


1904. 
Quinine not given systematically. 


1905. 
Quinine given systematically. 


Number 
Examined. 


Number 
Infected. 


Percentage 
Infected. 


Number 
Examined. 


Number 
Infected. 


Percentage 
Infected. 


I 
2 

3 
4 

Total . 


16 

41 

12 


10 
16 

12 


62-5 
37-8 

100-0 


17 

40 

17 

17 


2 

5 

2 

4 


II.7 

12-5 

II-O 

23-5 


69 


38 


55-5 


91 


13 


II-2 



* By daily quinine administration for coolies I mean six days out of 
seven, namely, on the working days. 
106 



VALUE OF QUININE ADMINISTRATION 107 



Table showing the Number of Children infected with Malaria in 
November and December on Estates on which Quinine was not 
given systematically in either 1904 or 1905. 



Estate 
Number. 


1904. 


1905. 


Number 
Examined. 


Number 
Infected. 


Percentage 
Infected. 


Number 
Examined. 


Number 
Infected. 


Percentage 
Infected. 


5 
6 

7 
8 

Total . 


66 
25 


33 
7 


50-0 
28-0 


52 
13 
15 
16 


23 
6 

4 
II 


44-2 
46-0 
26.I 
687 


91 


40 


43-9 


96 


44 


45.8 



Table showing the Number of Coolies not at work on account of Malaria 
on the day of my Monthly Visit, November 1905. 

A. Estates where quinine is given systematically. 

B. Where it is not given. 



Estate 


A. 


Quinine Given. 


Estate 


B. Q 


uinine not Given. 














Number. 


Number 


Number 


Percentage 


Number. 


Number 


Number 


Percentage 




of 


with 


with 




of 


with 


with 




Coolies. 


Malaria. 


Malaria. 




Coolies. 


Malaria. 


Malaria. 


I 


70 





0-0 


5 


800 


33 


4.1 


2 


320 


2 


0-6 


6 


170 


12 


7-0 


3 


120 


I 


0-8 


7 


250 


13 


5-2 


4 


So 


5 


6-2 




212 


27 


12.6 


590 


8 


1-3 




H32 


85 


5 .8 



An estate bears the same number in all the tables. The 
administration of quinine is doubtful in estate No. 4. From 
it the manager was dismissed. 

These figures appeared to me to be most encouraging, and I 
said of quinine administration, in a Presidential Address before 
the Native States Division of the British Medical Association 
in Ipoh in 1906: — 

" Our Hopes. — Although many, without thinking, consider it 
acts merely by curing the individual after he has been infected, 
and aborting threatened attacks, it is in reality much more than 
this. It is a real prophylaxis, for by cutting short attacks, it 
diminishes the chances of mosquitoes becoming infected, and 



108 ON QUININE 

thus prevents other coolies from ever becoming infected. It is 
by no means a case of locking the stable door after the horse 
has been stolen, and there need be no hesitation in advocating 
its use. 

" Nevertheless, it is not a method which commands my 
unqualified approval, for the simple reason that it requires too 
much of the manager. He has other work to do, work which 
must be shown as done in his monthly report, or his directors 
will want to know why? Instead of spending perhaps the best 
and coolest time of the morning giving out quinine, he wishes 
to go out into the field. Again, the manager himself may fall 
ill, and there may be no one to see the coolies take their 
quinine. A new manager may come, and he has probably to 
learn by bitter experience, that the hours spent in giving out 
quinine are not only well spent, but must be so spent, if the 
labour force is to be kept together. Again, it is not given to 
every manager to have the patience to see every coolie, and 
especially every child, gets its quinine ration, and with new 
coolies more or less undisciplined, there may be great difficulty 
in getting down the quinine, as the coolie has little faith in it. 
It is a great point when a ' Kangany ' realises the value of 
quinine, but at the same time, no native can be trusted entirely 
with this, and it is a considerable call on the manager's time. 
Then when the necessity appears to pass off, there will always 
be a tendency to slackness, as with all human efforts. There- 
fore, while I value the method, I consider the call it makes on 
the manager, a very serious drawback." 

I hoped by giving quinine daily to those who had malaria, 
to prevent the formation of gametocytes which would infect 
mosquitoes ; and that if any new coolies should chance to become 
infected, quinine twice a week would destroy the parasites before 
they had time to develop to numbers sufficient to give fever to 
the host. As will be seen later, neither of these hopes have been 
fulfilled, since it has been impossible to give the large doses which 
would be necessary to attain this object in people who are 
working. And secondly, as I shall show later, what may be a 
sufficient dose when malaria is not intense, is quite insufficient 
when it is. My advice in 1906 was as follows : — 

"(1) That every coolie should get a cup of hot coffee 
before starting work in the morning. (2) That twice a week 
every coolie should get ten grains of quinine, and every 
child five grains. (3) That every coolie who has fever should 
have a mark put against his name on the check roll when 
he resumes work, should receive no ' Name ' for his day's 



THE VALUE OF QUININE 



109 



work until he has taken a dose of quinine, in the manager's 
presence." 

This advice was followed on one estate which was just 
being opened up, and the result was a total failure of the 
quinine even to hold the disease in check ; so that on 
6th November every coolie was put on 10 grains of quinine 
daily, and those who were not at work on 20 grains ; it 
being assumed that, if he did not work he might be unwell ; 
and that the extra dose of quinine would do him good by 
preventing an attack of fever, even if he had no pyrexia at the 
time. The effect of the daily dose was to reduce sickness to 
a marked extent, as the following table shows. 

Table showing the Number of Coolies who were unable to work from 
"Fever" and "Other Diseases" during certain months in 1906 
and 1907. 





1906. 


1907. 


Oct. 


Nov. 


Deo. 


Jan. 


Feb. 


Mar. 


April. 


May. 


June. 


Fever .... 
Other diseases 

Total . 
No. of Coolies on the Estate . 


136 
283 
220 


152 
195 

347 
2 45 


5° 
83 

133 
243 


38 
81 

119 

247 


19 

41 

60 
248 


14 

54 
68 

234 


14 

54 
68 

255 


5 
H 

19 

322 


8 
10 

18 
228 



It is interesting to observe that what we saw when malaria 
was reduced in Klang Town, namely the reduction in diseases 
other than those recognised by the general population of 
malaria, was reduced on this estate likewise with the reduction 
of the amount of malaria. 

The economic effect of the malaria and the effect of the 
quinine can also be observed from the table on p. no. 

The decrease in the out-turn of the labour of 1907 was due 
to unsatisfactory work of the dresser in charge, who had to be 
dismissed. It was found he was seriously neglecting his duties, 
as the coolies who did not turn out to work were not sought 
for and given the extra quinine. The unreliableness of native 
dressers will always be one of the great drawbacks to quinine 
administration. In this instance, the dresser, who by his hard 
work had helped so materially to obtain such good results in 



110 ON QUININE 

1906 and the early part of 1907, now became lazy and mis- 
chievous for no apparent reason, and ultimately was convicted 
and sent to prison for six months for attempting to cause riot 
by setting one class of coolie against another. 

Table showing the Number of Coolies on this Estate, the Number of 
Days which it would have been possible for these Coolies to work 
had they worked every working day of the month, the Number of 
Days they actually worked, and the Percentage this forms of the 
possible Working Days. 





Number of 
Coolies. 


Number of 


Number of 


Percentage of 


Month. 


Possible 


Days 


Possible 




Working Days. 


Actually Worked. 


Days Worked. 


1906. 










May . 


69 


1241 


1050 


84.6 


June. 


135 


2499 


2IOO 


84.O 


July . 


190 


4914 


3670 


74-6 


August 


299 


8073 


5590 


69-2 


September 


248 


6200 


4257 


687 


October . 


220 


538o 


3352 


62.3 


November. 


245 


6366 


4238 


66-5 


December . 


243 


6318 


4584 


72-5 


1907. 










January . 


247 


6175 


4907 


79.0 


February . 


248 


5952 


4829 


81. 1 


March 


248 






79-8 


April 










76-9 


June. 










83-0 


July . . . 










84-0 


August 










90-0 


September 










gO'O 


October 










79-0 


November 










76-0 


December . 










77-o 



The best results I have obtained are shown in the following 
table (Seafield Estate) : — 





1906. 


1906. 


1907. 


1908. 


1909. 


Average population . 




175 


380 


399 




Blood— 

Number examined 
Per cent, infected . 


16 
68.7 


9 

76 








Spleen — 

Number examined 
Per cent, enlarged 


16 
56 


17 
88 


23 
39 




47 
62 


Deaths per iooo, Div. I. . 
„ Div. II. . 




114 


66 
60 


34 
27 





THE LIMITATIONS OF QUININE 111 

Writing in 1906 I described the condition of this estate in 
1905 as follows : — 

"In November, out of 212 coolies I found 27 down with 
fever on one day (where) 5 children had died in one week : 
(where) coolies were bolting daily, and the work of the estate 
was almost paralysed. This was followed by an outbreak of 
dysentery, and it was in the month of February before malaria 
was got in hand." 

In 1906 or the beginning of 1907 it was discovered that 
the pills which were supposed to contain 4 grains of quinine 
contained much less than that amount, namely about one grain. 
The dose was then increased with a steady improvement in the 
death rate each year. It is interesting that the fall held good 
for each division of the estate. In 1905 in the month of October 
245 coolies worked 3393 days, or 58 per cent, of the possible 
working days. In October 1906, 260 coolies worked 21 31 days, 
70-9 per cent, of the possible. 

The economic effect of this quinine administration has been 
that the present small labour force now maintains in perfect 
order some 2000 acres at a minimum cost. That it is not due 
to any improvement in the health of the estate from other 
causes, will be seen from the following paragraphs relating to 
the limitations of quinine. 

The Limitations of Quinine. — In 1908 and 1909 considerable 
attention was being paid to the presence of the ankylostoma 
worm in coolies, and at the request of the Institute for Medical 
Research, I arranged in April 1909 for the examination of 
a large number of coolies. I chose for this purpose a healthy 
estate where no quinine was given, and the above-mentioned 
estate, on which quinine was being administered with such 
satisfactory results. 

The result was to show that while ankylostoma was present in 
large numbers on both estates, on the healthy one (Estate " V ") 
2 out of 160, or 1-3 per cent, of the coolies had parasites in their 
peripheral blood, and on the other estate no fewer than 56 out 
of 215 or 26 per cent, showed the parasite. The examinations 
were made by Dr A. T. Stanton of the Institute to whom 
I am indebted for the figures. 

These results, in view of the splendid physique and work 
done by the force, appeared to warrant further inquiry. I 
accordingly visited the estate and examined all the coolies on 



112 ON QUININE 

it, paying particular attention to those who had been shown to 
have had parasites in their blood. I separated the 56 as follows : — 

Well developed, well nourished, and apparently in perfect health 42 
Less well developed and nourished, but still apparently in 

good health and fit for work . . . .5 

Anaemic ....... 1 

In hospital. 

Died .... 

Deserted . 
Paid off ■ 



1 

1 

_4 
56 



In other words, 75 per cent, of the coolies with parasites in 
their peripheral blood were apparently in the most perfect 
health, while 87-5 per cent, were in good health and fit for 
work. Of the 48 seen 30 or 62 per cent, had enlarged spleens, 
and of the whole labour force of 345 ■ I found 174 or 50-4 per 
cent, with enlargement. 

On one division the coolies were getting 6 and on the other 
8 grains, with double doses when they were ill or off work, 
often quinine in solution. As at this time mosquitoes were 
breeding freely on the estate in the ravines, close to which the 
coolies were living, and adult A. maculatus could be obtained 
in the lines at any time, this observation is of the greatest 
value in determining the effect of quinine. It clearly demon- 
strates that, while keeping the malaria in check, so that the 
coolies could carry on their work, three years' administration 
of the drug had entirely failed to eradicate the disease. That 
the estate is really as unhealthy as ever is shown by the visitors 
to it, who contract malaria in about ten days, and even the 
head kangany suffered severely from malaria on his return 
to the estate after a visit to India. 

Finally, out of nineteen A. maculatus captured in the lines, 
four or 21 per cent, had malaria, two with zygotes, one with 
sporozoites, and one with both zygotes and sporozoites. 

Desiring to have further information on this important 
point, I took the blood of every man, woman, and child on an 
estate on which quinine was being given in the most thorough 
and systematic manner. The doses being given were 10 grains 
daily to each adult who worked, and 20 to those who did not 
work, the latter being given in solution. To the children 
5 grains were given daily, and double doses also to those 



THE LIMITATIONS OF QUININE 113 

who did not work. Mr R. W. B. Lazaroo kindly examined the 
slides for me, and reported as follows : — 

Of the 29 children, the results were as follows : — 



Malignant parasites (subtertian) 
Benign Tertian 


5 
2 


Per Cent. 
17-27 -j 

6-8 9 \ 27-58 


Quartan 


1 


3-44 > 


No parasites seen 


21 




he 125 adults the results were : — 

Malignant (subtertian) 
Benign Tertian 


22 

• 15 
3 


Per Cent. 
12-0 -I 

3-4 [ i8-4 


„ Quartan 


5 


4-0 J 


No parasites seen 


102 





_I2_5 

Of the whole 154 the percentage found with parasites in the 
peripheral blood was 20-12. 

These figures agree very closely with the ones obtained by 
Dr Stanton, and they at once supply the reason why no 
improvement has taken place in the hill land estates despite 
the use of quinine in what appear very large doses for constant 
administration. 

Now this failure to eradicate malaria falls into line with 
our knowledge generally of quinine. I would indicate the 
following as the limitations of quinine: — 

(1) However thorough the dosing has been, malaria is very 
liable to return to a patient although the possibility of re- 
infection is excluded. In other words quinine does not poison 
the parasite outright. 

(2) When a person is attacked by malignant malaria 
(subtertian) for the first time, even with the most thorough 
administration of quinine in solution, some four or five days 
elapse before the temperature falls, and Rogers has published 
figures which show that 60 grains daily have no advantage 
over 20 grains or less. 

(3) Quinine has little if any effect on, the sexual forms of the 
parasite in the peripheral blood. I have watched crescents in 
a man's blood for three weeks during which he was taking 20 
grains of quinine solution daily, and after all pyrexia had gone.* 

(4) In bad epidemics I have watched cases of malaria 

* [1920. — Ross and Thomson have shown there is a connection between 
the asexual and sexual parasites in the peripheral blood. — M. W.] 



114 ON QUININE 

admitted to hospital, who have had no pyrexia, but rather who 
have been in the algid state ; who despite the administration 
of quinine by the mouth, by the rectum, and intramuscularly 
to the extent of 40 grains daily, have continued for four 
days in this algid condition and then died. During this time 
the skin was in a condition of a cold clammy sweat. No 
diminution appeared in the number of parasites in the blood. 
The patient apparently failed to react any way. 

(5) It is common experience that a patient, particularly 
if he is suffering from benign tertian malaria, must be put to 
bed before pyrexia will leave him, even when on full doses 
of quinine. 

Finally, when we remember that thousands and thousands 
of people, who do not take nor have the opportunity of taking 
quinine, recover from the disease yearly, it is evident that the 
human subject of the disease must depend on some power 
within himself to save him from death. Daniels, 20 in his 
Presidential Address to the British Medical Association in 
1909 in Belfast, appears to me to strike the right note when 
he insists that the protozoal diseases, of which malaria is a 
member, may persist for years without sexual regeneration, 
and despite any drugs which may be given ; and that freedom 
from the disease can be acquired only by the development of 
resistant powers within the human host. It is when we con- 
sider malaria as an infection of the human host by a parasite, 
which in the majority of infections lasts for at least three or 
four months, and in exceptional cases for years ; in which the 
relationship of the parasite to its host is that of enemies at 
constant war; where for a time first one and then the other 
may be in the ascendant ; and where victory in the end may 
be to either, that we can understand the apparently con- 
tradictory results of quinine. 

When from any cause the health of the host is depressed, 
the parasite increases in numbers and may be found in the 
peripheral blood. As the struggle continues and the life of 
the parasite is threatened, in harmony with the rule of nature 
generally, the parasite produces the sexual forms destined to 
continue its existence as a species. Thus, from time to time, 
the human host becomes dangerous to others, if anophelines 
which form a congenial breeding-place for the sexual forms 
{i.e., capable of carrying malaria) are present. 



MENSTRUATION AND RELAPSES 115 

When, on the other hand, the health of the host is improved 
from any cause, the parasites are reduced in numbers and may 
disappear from the peripheral blood. The parasites may, in 
the end, die or be killed out by the host. It is not unlikely 
that two separate immunities are required by the host before 
the parasite is destroyed. It appears to me to be not un- 
common for the host to become immune to the poison causing 
pyrexia long before it acquires powers to reduce the number 
of parasites ; for cases with numerous parasites and without 
pyrexia over considerable periods are not uncommon, indeed 
are recorded by every writer on malaria.* The true action 
of quinine appears to be to assist the human host in working 
out for himself the resistant power which will ultimately free 
him from the disease. It acts either by attenuating the virus 
within the host, or by increasing the resisting power of the 
host in some unknown way, or possibly by both. Without 
quinine in many cases, especially in very unhealthy spots, 
the human host would die before he had acquired his resistant 
powers. We thus see that, if quinine in sufficient doses be 
given, the man will gradually overcome the parasites, and 
apparently suffer little from them ; but at the same time we 
see that during this period he is capable of infecting others. 
The man is for a time a "malaria carrier" not unlike the 
typhoid carrier. 

There must be an optimum dose of quinine, possibly it 
varies with the individual, and, from time to time, in the same 
individual ; but whatever that dose be, it must bear a close 
resemblance to the ordinary therapeutic dose. 

Finally if, as has been shown, the immunity from malaria 
produced by quinine leaves the patient infective while he is 
acquiring the immunity, then it will be impossible in the 
presence of many anophelines, and in the presence of many 
new arrivals (such as newly born children) ever to eradicate 

* Among the causes which predispose to a malaria relapse, menstruation 
is a powerful one. Menstruation frequently is followed by, and sometimes 
accompanied by, a malaria attack. I have a record of a European who, 
when in England, had six attacks of malaria following at once on six 
regular menstrual periods. On her return to the tropics, and after an 
interval of many months, she had a return of severe pyrexia within two 
days of a more than usually severe monthly period. (1920. — On account of 
these relapses at each period, she had to be invalided permanently from the 
tropics.) 

K 



" 



116 ON QUININE 

malaria by quinine. It follows, too, that if drainage be an 
alternative, even although more expensive, drainage must be 
the method which should be adopted. Even if a community 
possessed no money for drainage, money might be borrowed 
with which to carry out the works, and at the end there would 
be an asset to show for the expenditure. Borrowing, however, 
would be impossible if the object were to buy quinine, since 
in the end nothing could be shown for the money, except a 
people still liable to malaria, and possibly some agriculture which 
could not be maintained without the constant use of the drug. 

Observations on Quinine Administration. 

Time and Form. — When I first began quinine administration 
systematically to large bodies of coolies, I advised quinine 
sulphate in solution and in the morning. I advised the solution 
because in solution its action is more certain, and it would 
thus be possible to use a smaller quantity of the drug ; I 
advised the morning because the parasites usually sporulate 
in the forenoon, and consequently would then meet with the 
quinine in full strength. 

In practice it was found that there were serious objections 
both to the time and the form of administration. In solution 
the action was so certain, that in io-grain doses cinchonism 
was so marked that the coolies could not work in the sun. In 
addition they were frequently sick after the dose ; ultimately 
it was suspected that they deliberately vomited the dose to 
avoid the unpleasant after-effects. 

Since then it has been given when work is finished for the 
day — that is about 2.30 P.M. 

When I decided to abandon the solution I considered 
that the compressed forms as usually supplied were too much 
compressed, and coolies were taught to make quinine pills 
with bread. They became astonishingly expert at this. The 
pills were supposed to contain 4 grains of quinine, but after 
a time it was found they were putting in too large a proportion 
of bread as the pills were thereby more easily made. 

In order to standardise the dose, in 1907 I obtained machines 
from England, and hoped to make tablets, compressing the drug 
just enough to keep it in a mass. The machines were not a 
success, as the rate at which the tablets could be turned out 



OBSERVATIONS ON QUININE ADMINISTRATION 117 

was far below that of the coolie making pills by hand, and 
quite insufficient to meet the demand. I therefore returned 
to the pills, but now (1909) have them made by mixing dry 
quinine sulphate with so much gum solution, that when made 
the pills can be crushed easily between the finger and thumb. 
There are at the present moment just over 4000 coolies taking 
10 grains daily, with double doses when off work.* 

The efficiency with which the drug is administered 
depends on the manager of the estate. Each year the 
drug is being given over larger areas and with greater efficiency, 
as its value is being better recognised. A change of manager 
is usually followed by less care being taken to give the drug, 
and this is a serious drawback. 

Europeans tell me that it is impossible to continue the use 
of quinine solution for any length of time. If taken in the 
morning, they cannot take food and cannot work in the sun. 
If taken at night, even dry quinine prevents sleep. I hoped 
at one time that, if taken at night, larger doses could be taken, 
the effects of which would pass off during sleep. But men are 
unanimous that taken at this time it prevents proper sleep, 
and the drug is now rarely taken at night. 

Quinine sulphate in powder often fails to have any effect 
on an attack of malaria if there is gastric disturbance ; this 
even when 20 or 30 grains are given in the course of twenty- 
four hours, and for a period of a week. In such cases I give 
quinine hydrochloride with a little morphia in solution. This 
effectively controls the sickness, and the temperature is usually 
down in thirty-six hours. I have often wished to try the old 
native remedy of opium with the quinine, but have never felt 
quite justified in doing so, on a large enough scale to be of 
value. 

Warburg's tincture I have used both for pyrexial attacks 
and as a preventive. It appears to have no special advantage 
over a simple mixture of hydrochloride and morphia. I have 
also given it over considerable periods, combined with additional 
quinine, to bring the dose of the latter up to 15 or 10 grains 
as the case might be. I cannot see that it has any special 
advantage. 

Small children learn to swallow pills very quickly. For 

* (1920). — For some years the quinine has been given in gelatine 
capsules. 



118 ON QUININE 

infants I find the easiest way to administer quinine, is to give 
euchinine (quinine ethyl carbonate) broken up in a little 
sweetened condensed milk. 

On estates, where quinine has been much used, it is not 
uncommon to find coolies ask for solution in preference to pills, 
when they have fever or suspect an attack is coming on. 
Kanganies are often found to carry pills in their pockets, and 
give them out to any coolie who complains or asks for them 
during the day. On the other hand, I recently found the 
conductor on an estate, where quinine has been given daily 
to the coolies for four years with the best results, who had 
suffered from malaria himself and taken quinine for it, would 
not give his wife quinine when she was almost dead with 
malaria, until literally forced to do so. If such happens with 
a native who reads and writes English, who lives on an estate, 
where if on any place in the world quinine has shown its power 
to control malaria, it is impossible to believe that native 
populations will ever be induced voluntarily to take quinine 
in such doses as will effect any marked difference on the death 
rate of the disease. 

Although quinine sulphate may not be absorbed when there 
is gastric disturbance, there can be no question about its being 
absorbed in the majority of cases. For a week after a coolie 
or a European begins the daily consumption of quinine powder 
or pills, quite definite symptoms are felt in the head. After 
that period no unpleasantness is experienced, unless the dose 
be increased. Instinctively men have learned to take their 
total quantity broken up into two or three doses. And my 
object now on the most intensely malarious places is to have 
from 10 to 15 grains taken daily without producing symptoms. 

After an attack of malaria I advise 20 grains in solution 
daily for a week, and then reduce the dose to 10 grains in pill 
form, resuming 20 grains should the person feel unwell, and 
find his temperature ioo° F. or more taken in the mouth. 

I prefer the sulphate for continuous use because the more 
soluble forms are more apt to produce cinchonism. There 
is reason to believe the sulphate is absorbed not only from 
the stomach, but from the intestines. Its slower rate of 
absorption, therefore, leads to less violent fluctuation in the 
amount circulating in the blood, than where more soluble 
preparations are used. It has the advantage, too, that a 



OBSERVATIONS ON QUININE ADMINISTRATION 119 

dose will, therefore, have a more continuous action, and 
be present in the tissues and fluid for a longer period, than 
where the preparation is more rapidly absorbed and pre- 
sumably more rapidly eliminated or destroyed. 

Nor is it an unimportant advantage where thousands 
of coolies are receiving comparatively large doses daily, that 
the price of the sulphate is some 30 to 50 per cent, less than 
the other common preparations. 

(1920). — Towards the end of 1912 I contracted malaria 
for the first time. It was a severe attack of benign tertian 
malaria with continuous fever for four days. After the febrile 
attack was over, the attempt to resume ordinary diet was 
followed by acute gastritis, and I had an unusually favourable 
opportunity of observing the effects of several salts of quinine. 

Very soon I came to prefer a simple watery solution of 
quinine bihydrochloride flavoured with orange or ginger. 
Twenty grains divided into three doses were taken daily 
with meals. It was my custom to swallow a few mouthfuls 
of some liquid, such as tea, coffee, or soup ; then to take 
the quinine ; and afterwards proceed with the meal. The 
taste of the quinine lasted only a minute or two. After 
the first week I was not conscious of any ringing of the 
ears or other symptoms of cinchonism. 

When the quinine was taken half an hour before the 
meal, cinchonism was pronounced and unpleasant ; when taken 
after the meal, it frequently produced "acidity." Curiously 
enough tabloids and capsules taken with or after a meal 
produced the same " acidity " and discomfort. 

For six months I took 20 grains daily in solution, and 
rapidly recovered health. No relapse occurred while I was 
taking it, or after I stopped it. 

In 1914 I contracted what there is good reason to believe 
was a new infection of benign tertian malaria. For it, I 
took quinine in the same doses for five months, with the 
same happy result as in 1912. Since stopping the drug 
1 have had no relapse. 

(1909) Relation of Dose to Intensity of Malaria. — I think the 
same dose of quinine may be of more apparent value where the 
amount of malaria is small, than where it is great. I have 
long been of the opinion, too, that what is supposed to be a 
relapse, is often in reality a new infection. It is impossible 



120 ON QUININE 

to decide with absolute certainty ; but there is a certain 
amount of evidence, beyond the few cases where we find 
different parasites in different attacks. 

For example, when in the service of Government, it was 
one of my duties to visit a place called Jugra at regular 
intervals. Jugra is intensely malarious. Government servants 
and their wives and families suffer severely from the disease. 
The place is consequently very unpopular, and at each visit 
I was interviewed by one or more applicants for transfer 
on medical grounds. As long as Government decided to keep 
Jugra as a district centre, so long must its servants remain ; and 
I refused to grant certificates on the ground of ill-health, 
if the complaint was merely of attacks of malaria. I advised 
daily quinine, and it was given to the police daily by a 
dresser from the hospital. 

Before I gave a certificate I had to be satisfied that some 
danger of serious damage to health existed. I thus had an oppor- 
tunity of watching people progressively deteriorate, and when I 
considered there was any real danger, I recommended transfer. 
This was, in the case of the police and clerks, often to Klang ; 
and I was then still able to keep them under observation. 
It was interesting to observe the steady improvement, with 
but few relapses in most cases, after transfer to a non-malarious 
place. Had their almost constant attacks of fever when 
in Jugra been merely relapses, these would certainly not 
have ceased so suddenly when the patient came to Klang, 
nor would the improvement in health have begun so soon, 
and been so marked ; and this, when I am sure they were 
taking less quinine than when in Jugra, and perhaps none 
at all. 

What appears to bear out the same idea is the severity 
of the attacks of malaria in Europeans on intensely malarious 
estates. These patients are constantly going down with 
malaria, even when on daily doses of 10 grains of the sulphate. 
A short holiday usually enables them to recover ; but attacks 
recur soon after their return to work, often in the usual period 
necessary for new infections to manifest themselves. Should 
they permanently leave the unhealthy place, they rapidly 
recover, even when their new work and the climatic conditions 
under which they labour are identical with that of the 
unhealthy place they have left. An observation on Estate 



REINFECTIONS 121 

" RR " has some bearing on this point. This estate is in 
three divisions, and there is a European bungalow on 
each. Bungalow I. is situated between the lines marked 
ioo and those marked 37. It is on a ravine in which I 
have not been able to find A. maculatus, and which I 
think is probably unsuitable for them. Bungalow II. and 
Bungalow III. are near to ravines in which A. maculatus 
swarm, and the spleen rate of the lines, if we exclude new 
arrivals, is practically 100. The history of the bungalows 
is that while I. is malarious, II. and III. are intensely so. 

In Bungalow I. six Europeans, who from time to time 
have lived there, have had attacks, with the exception of 
one who took 10 grains of quinine daily for the two years he 
was there. One of the five attacked had only two attacks, 
and these at intervals of a year. The others suffered more 
severely, but soon became free on taking the drug daily ; 
while neglect just as certainly led to new attacks. Ten 
servants had malaria in 1907, and there was difficulty in 
keeping servants, until they were compelled to take the drug 
under supervision. It will thus be seen that the bungalow 
was malarious, but not intensely so. 

Bungalow II. has been more malarious, and the three 
Europeans who have lived in it have been severely attacked 
time and again, and have frequently been compelled to go on 
periods of sick leave. 

Now in 1909 it was necessary to rearrange the work of the 
estate. A and B who had lived in Bungalow I. (A never 
having had an attack, and B who had suffered from only two 
attacks) were transferred to Bungalows III. and II. respectively, 
while C was transferred from II. to I. A and B now suffered 
very severely from malaria, and both were invalided for a time, 
and this although they were taking the same amount of quinine 
as when in Bungalow I. C, on the other hand, ceased to have 
attacks, and gradually reduced his daily dose, until, when taking 
only about 5 grains a week, he had a sharp attack, which put 
him on to his full doses again. That there is no improvement 
in the health of Bungalow I. is seen from D, who about the 
same time arrived on the estate, refused to take quinine, and 
had so severe an attack that he had to be sent on leave for 
a month. 

Now the work on all the divisions is practically the same. 



122 ON QUININE 

It is impossible to believe that A and B were never infected 
in Bungalow I. during the two years they lived there, and when 
the servants and other Europeans suffered frequently from the 
disease. The only explanation appears to me to be that the 
dose of quinine which kept them free from symptoms in 
Bungalow I. was insufficient to do so when they had to over- 
come larger and more frequent infections. 

Again we saw (p. ioo) that the quinine which appeared to 
keep the old coolies in health in 1906, failed to keep the new 
arrivals in health, but that " from the new it (malaria) spread 
to the old " and the dose of all had to be increased. From this 
I concluded that the large number of new coolies had raised 
the percentage of infected mosquitoes on the estates, and that 
by old coolies infecting new, and these again infecting the old, 
a vicious circle was established which could only be broken by 
the gradual establishment of immunity among both old and new. 

The following is another instance of a large dose (the 
largest I have known taken continuously) giving protection 
where smaller doses have failed. The individual (a close 
relative of my own) took 20 grains of quinine sulphate daily 
for three months. He had previously suffered so severely 
from malaria on an unhealthy estate, although he had been 
taking quinine in 10-grain doses, that he had to give up his 
post as manager. He had twice to go to a hill station to 
recover his health ; ultimately he resigned his post. I was 
anxiously considering the necessity of invaliding him home. 
He was so breathless he could walk only a few yards ; his 
weight had fallen to 136 pounds. He was, however, determined 
not to go to England, and took a post on another, but smaller, 
intensely malarious estate ; one where each of his predecessors 
had left a wreck. 

Its spleen rate has been 100 for some years. He took 
20 grains of quinine sulphate in gelatine capsules daily, 
taking 5 grains at a dose. In two months his weight had 
gone up from 136 to 164 pounds. He said he had an excellent 
appetite, and was soon playing in an interstate rugby match. 
After three months he reduced the dose to 15 grains daily, 
and he has been on this dose for four months. 

I have kept a watch on him, and have critically examined 
him, not without some anxiety, lest the drug should do harm. 
But I cannot recommend a reduction to less than 15 grains 



INTENSE MALARIA 123 

as long as he is well, and when to take less might spell disaster. 
The fine bungalow in which he lives is at the top of a ravine, 
and has been so unhealthy in the past that its abandonment 
was suggested by the owners. A. maculatus breeds freely in 
the ravine. 

The marked contrast between this planter whose health 
improved, when taking large doses, and the progressive de- 
terioration in his predecessors, who were on smaller doses, is 
so striking as to be a matter of general comment. And I think 
we are driven to the conclusion that in this extremely malarious 
place, larger doses are required than are usually taken in 
malarious places. 

Each year has only strengthened my view that, to keep 
a European or a labour force in apparent health, the amount 
of quinine to be given bears a relation to the amount of malaria 
in the place at the time. The more the malaria the more 
frequently, and in larger doses, must the drug be given. 

This would explain, too, the contradictory results obtained 
by various observers when quinine has been given as a 
prophylactic. Not only does it explain and bring these contra- 
dictory observations into line, but the observations recorded 
here help us to understand the cause of the variation of the 
intensity of malaria in different places, and in the same place 
from time to time. 

From clinical observation, I think we are justified in 
concluding that the very frequent attacks, from which men 
suffer when in very malarious places as compared with the few 
attacks when removed to non-malarious places, are due to fresh 
infections, and not to relapses. If such an explanation of the 
more frequent attacks be accepted, then the necessity for the 
administration of quinine in larger quantities, approaching 
ordinary therapeutic doses, in the more malarious places, and 
at times of the greater prevalence of the disease, is easily 
understood. The human host has larger quantities of malarial 
parasites injected into him, and thus requires an increased 
protection by quinine. 

Again, on the flat land, we saw that the nearer we were to 
the breeding-place of the anopheline — that is, the jungle — the 
greater the malaria : indeed, within the half-mile radius, it 
bears a definite ratio. We are forced, therefore, to believe that 
the intensity of malaria bears a definite relation to the number 



124 ON QUININE 

of anophelines in the air, to the number of times a person is 
bitten, and to the number of infections he receives. 

Similarly, on the hilly land, observations from all time have 
shown that the head of a ravine is the most malarious ; it is 
nearest to the chief breeding-places of the anophelines. The 
most malarious bungalows in the country are those situated at 
the head of, or close to, a ravine. The once notorious bungalow 
on Drummond's Hill, Taiping, had its servants' quarters over 
a ravine. Now it is obvious that the inhabitants of such a place 
must be bitten oftener, and infected oftener, than those living 
at a distance from the breeding-place. They are infected time 
and again by their own parasites after passing through a 
mosquito in which, too, by the sexual reproduction that occurs 
in the mosquito, it is not improbable the parasites have 
acquired an exalted virulence. 

Thus again we are forced to believe that the greater 
intensity and persistence of malaria in the hilly land is due 
to the greater number of anophelines, and the greater number 
of infections which the persons in these regions receive. 

Now if the foregoing be true, it would follow that malaria 
would also be intensified by increasing the percentage of the 
infected mosquitoes, without increasing the total number, which 
bite. And we find it to be so in fact, as seen from the infection 
of old from new coolies. The introduction of many new 
non-immune coolies, who almost simultaneously contracted 
malaria from the few still infectious old coolies, soon raised 
the percentage of persons with parasites in their peripheral 
blood, and capable of infecting mosquitoes to a higher degree 
than when there were only old coolies, most of whom had 
acquired a considerable amount of immunity and control over 
their parasites. A higher percentage of mosquitoes soon 
becomes infected, and these, in biting old and new coolies 
indiscriminately, soon increases the infection of the former and 
leads to their again suffering from attacks of the disease. 

The intensity of malaria therefore depends, in my opinion, 
on the absolute number of infected mosquitoes in a locality, 
and anything which increases the number of malaria-carrying 
anophelines therefore increases the intensity of malaria.* 

Many of the factors, which influenced the prevalence and 

* [1920. — This subject is discussed in an illuminating manner by 
Ross in Chapter V. of his Prei'eniion of Malaria. — M. W.] 



ILL-EFFECTS OF QUININE 125 

intensity of malaria, were well known to our fathers before 
us. Such were disturbance of soil, interference with drainage, 
seasonal variations in temperature and rainfall, etc., etc., and 
it is extremely interesting to see that although their deductions 
as to the cause of malaria were incorrect, their observations 
were marvellously correct. In childhood's language they were 
" very, very hot " in their search for one of nature's most 
cunningly hidden secrets ; and I desire to pay my humble 
tribute of respect to their memories. 

Finally, if these observations be correct and the deductions 
be sound, the anopheline is the factor in the production 
of malaria which must be eliminated, if any permanent 
improvement is to take place. 

Ill-Effects of Quinine. — It has been with a due sense 
of responsibility, and no little anxiety, that I have found myself 
the instrument in causing large numbers of people to take 
quinine for prolonged periods in doses which appear excessive 
to many, and doses which year to year tend to increase 
in amount. I have watched the effect of its administration 
with care, and if it is producing any ill-effects, they are of such 
a nature as not easily to be detected — at any rate I have 
not detected them — and they are of infinitely less consequence 
than malaria. 

I have rarely given more than 20 grains daily unless on 
microscopic examination the patient's blood was so full of 
parasites as to show there was immediate danger to life. In 
such cases I have given up to 40 grains mostly per rectum, 
retaining the mouth for the administration of nourishment. 

I have never seen a case of quinine blindness,* nor have 
I had in my practice any patient who complained of deafness 
or ear symptoms for more than a few days. Occasionally 
a patient, the subject of malaria who does not take quinine 
in sufficient doses, complains of " indigestion." If on sulphate, 
I may order hydrochloride in increased doses, which usually 
puts him right. Time and again, when a man has complained 
that he has " not been up to the mark " and thought he 
has been taking too much of the drug, I have advised increasing 
instead of reducing the dose with the most satisfactory results ; 

* [1920. — I saw a case for the first time in 1918. But I have been told 
it has not been rare in this country when much larger doses have 
been given. — M. W.] 



126 ON QUININE 

so, too, when a man who has had malaria says he is feeling 
" particularly well." 

Miscarriage is often attributed to a dose of quinine. Yet 
I could quote instances of patients who have taken quinine 
throughout pregnancy and been delivered at full time. On 
the other hand an attack of malaria is notorious as producing 
abortion ; and if the attack comes on within the last two 
months of pregnancy, labour will almost certainly follow. 
It is true quinine is often given in these cases ; but the 
futility of quinine in ordinary doses when given to induce, 
or accelerate labour, in a healthy woman excludes the theory 
that quinine is the active agent in producing the abortion 
of the malarious patient. 

Occasionally, but very rarely, a cutaneous eruption appears, 
when doses of quinine are first given, but the rash disappears 
with the continued use of the drug. One man when first 
put on 15 grains daily developed a severe nettle-rash which 
was intensely irritating. It disappeared within a week. 

[1920. — Since the above was written I met a lady in 
Scotland who has a real idiosyncrasy for quinine. Her 
husband, a medical man, informs me that she develops a 
severe dermatitis, with grave constitutional symptoms, even 
from 2 grains of the drug; and there is little doubt that 
a large dose would kill her.] 

Cost of Quinine Administration. — It must not be forgotten, 
too, that the administration of quinine in effective doses 
in a malarious locality is by no means an inexpensive method 
of combating malaria. To give 10 grains daily to 1000 people 
without any extra to those who actually have pyrexia for 
ten years, would cost about £1900 sterling* Such a sum, 
if lent by a Government to a community at a reasonable 
rate of interest, would free a very large area from malaria, 
if drainage methods suitable to the local anophelines were 
employed. And in ten years the community would have some 
years of prosperity and health in which to repay the loan. 
In the case of many small villages it would probably be 
possible to eradicate the breeding- places of anophelines, 
where they were in the midst of the community, at a mere 
fraction of the money which would be required to dose the 
population effectively with quinine even for a year. While 
* [1920. — The cost of quinine is now much greater. — M. W.] 



QUININE ADMINISTRATION AND DRAINAGE 127 

for larger communities the cost of drainage would be relatively 
much cheaper than in the case of the smaller ones, since 
the same expenditure would protect a relatively larger 
number of people. 

Relative Values of Quinine Administration and Drainage. — 
We have seen that quinine at its best, and when administered 
with a thoroughness, the result of a discipline impossible of 
attainment in an ordinary population, still leaves a large 
percentage of the population capable of infecting others. It 
can, therefore, never eradicate malaria in the presence of new 
comers, and where there are many anophelines. We have 
seen, too, that to attain this best result in a malarious place 
costs a fairly considerable sum. Quinine, therefore, in my 
opinion, cannot for a moment be ranked with drainage. 

It cannot be too strongly urged that efficient land drainage 
not only is a radical anti-malaria measure, but is of first-class 
importance in almost all forms of agriculture ; and that malaria 
is essentially a rural disease. In dry forms of culture, it often 
makes the difference between good land and bad land, between 
good crops and poor crops. And in wet culture it is no less 
important. Cromer insists that in Egypt, the success of 
irrigation depends no less on the channels for taking off the 
water than on the irrigation channels for its supply. It is 
notorious, too, that badly drained irrigated land is not only 
of less value agriculturally, but is also more malarious than 
irrigated land, where by means of an efferent system, the water 
on the land is more fully under control. 

Finally I would urge that when the time comes for unanimity 
as to what should be done, the malaria problem will still be, 
as it is, essentially a financial one. In the end the affected 
community must find the means of combating the disease. 
To me it appears that any means, which will enrich the 
population, will enable it to make greater effort to overcome 
the disease. If, by drainage, we can enrich not only the 
people and the land, but by the same measure help to reduce 
the disease, drainage must be the measure of first importance. 

Whether quinine be supplied free by a Government or sold 
at cost price or at a loss to the Government, a price is being 
paid ; and the people are in reality being assessed an amount, 
however small, which would still have paid the interest on a 
loan for a radical drainage work. Perhaps the work would 



128 ON QUININE 

only be a small one, but no matter ; for it would definitely 
and for all time, if upkept, place the inhabitants beyond the 
reach of the disease. 

It is here that I think a Government can help to break 
the vicious circle which makes the malarious poor and the 
poor malarious, and can assist a people to initiate drainage 
works, which from poverty they themselves cannot begin ; 
even if Government cannot pay for drainage works out of 
revenue, then by pledging its credit, a Government can obtain 
money on loan. Both capital and interest can be paid by 
assessment of the land benefited.* 

Of course care must be taken that the works will improve 
the area ; to me it appears that in this direction lies the chief 
hope of eradicating malaria. 

Malaria over large areas cannot be eradicated in a day. 
But from what I have seen of the results of radical measures 
I feel strongly that by radical measures will the end be attained 
soonest ; that every success will help others ; that people will 
be saved who will never consent to take quinine in sufficient 
doses, if at all ; and that only by radical measures will be 
stopped the infection from, and the death of, the vast mass 
of those who suffer from " malaria sine pyrexia," those who 
fail to recognise they suffer from malaria, who as we saw from 
the Klang figures account for a very large percentage of the 
death rate of a malarious community. 

(1920). — The experience of the war bears out these con- 
clusions. In Salonica, where infection and re-infection by 
mosquitoes constantly occurred, quinine failed entirely to 
protect the troops, just as it had failed in the Malay States. 

In France, where re-infection did not take place, two 
divisions of malaria-stricken troops from Salonica were put 
in the firing line after two months' thorough administration 
of quinine, carried out under Lieutenant-Colonel J. Dalrymple, 
C.M.G. Fifteen grains in solution were given for fourteen 

* The following is Rule 2, under Section 6 of the Drainage Rate 
Enactment of Selangor, F.M.S. : — 

"The annual drainage rate shall ordinarily be an amount calculated to 
yield 5 per cent, on the original cost to the Government of the drainage 
works, together with the annual cost to the Government of the maintenance 
thereof. For the purpose of this rule all necessary sluice gates, and other 
protective works constructed in connection with the drainage of the whole 
or any portion of any drainage area, shall be deemed to be drainage 
works." 



CONCLUSIONS 129 

days; and for eight weeks 10 grains in solution. The strictest 
discipline was maintained in the administration. 

In England, where re-infection does not occur, the routine 
treatment of the War Office and Ministry of Pensions is 
10 grains of quinine daily in solution for nine to twelve weeks. 
Sir Ronald Ross, 21 who is consultant to both departments, 
writes : — 

" But can we not cure the cases outright by some therapia 
magna sterilisans ? I wish we could. 

" Unfortunately, though the War Office made innumerable 
experiments from early in 191 7 onwards, no really satisfactory 
result was obtained. For details the reader should study the 
forthcoming War Office publication, Observations on Malaria, 
by medical officers of the Army and others (Stationery Office), 
The Annals of Tropical Medicine and Parasitology (Liverpool) 
for the last two years, and many papers in the Lancet and other 
journals. We tried intravenous and intramuscular injections, 
heroic doses, kharsivan, and almost everything we could think 
of. Not one treatment provided a certain cure ; and the treat- 
ments which gave the most promising results required at least 
a month's stay in hospital, and were, I think, almost more severe 
than the disease. We still live in hopes ; but up to the present 
the daily dosage described above remains the best, as it is the 
oldest used. If I had malaria to-day, I should not dream of 
allowing any other ' cure ' to be practised on me." 



CHAPTER XIII 

SEAFIELD ESTATE AND SUBSOIL DRAINAGE 

A Grave Problem. — The two previous chapters have been a 
digression, but not unintentional. From them the reader will 
have learned how grave a problem confronted estates situated 
in the coastal hills. They were in the forks of dilemma; if 
their ravines were left in jungle they got malaria from 
A. umbrosus ; if their ravines were cleared, A. maculatus re- 
placed A. umbrosus, and took up the role of carrier. However 
scrupulously free from grass and weeds the ravine streams were 
kept, A. maculatus could not be driven out. Quinine given 
for years in large doses had proved a broken reed. What, then, 
could be done? Although, at this time, the elimination of 
malaria by control of mosquitoes was almost universally 
regarded as impracticable even for small towns, and for rural 
areas had not been discussed or suggested even in a tentative 
way, except by Ross himself, the ease with which it had been 
driven from the coastal plains and mangrove swamps, when 
the conditions there were made unsuitable for the anopheles, 
had convinced me that an attack on the ravine anopheles was 
the right policy. 

At that time I knew of no method of oiling or poisoning or 
polluting the water which promised success in rapid streams ; 
and I could think of nothing as suitable as a scheme of subsoil 
drainage. By carrying off all the springs and streams of the 
ravines in underground pipes, no water would be left for 
A. maculatus to breed in ; and presumably, if a large enough 
area were done, malaria would disappear. But what was a 
large enough area? and how were pipes to be laid in the 
ravines so that they would drain the springs and streams ; yet 
resist the tremendous scouring action of tropical storms? 

The Area to be Drained. — The proposal was that all land 
within a circle of a certain radius should be drained and freed 

130 



THE AREA TO BE DRAINED 131 

from the breeding-places of A. maculatus ; in the centre of 
the circle would be housed the labour force. There was little 
evidence of the distance that A. maculatus carried malaria from 
its breeding-places; certainly nothing comparable with spleen 
rates of children in relation to flat land jungle ; and these might 
mislead, if applied to hill land. The measurements on flat land 
were made in places for the most part with jungle on one side ; 
from one direction only A. umbrosus attacked. What would 
the malaria and the spleen rates have been had the observations 
been made on estates consisting of small circular areas carved 
out of, and completely surrounded by, the jungle of the coastal 
plains? Into such areas A. umbrosus would have flown to the 
centre from every point of the compass ; and spleen rates would 
have been of great value from the standpoint of the scientific 
sanitarian. But the information was not available ; estates were 
not developed so as to produce these conditions. 

There were two other considerations to be weighed. Into 
the hill land sanitary circle, which it was proposed to create, 
A. maculatus would not, fly from all points of the compass. 
In hill land part of the circle would be low ground and 
ravines, which would breed mosquitoes; but another part 
would be high ground, which would be harmless. The pro- 
portion between the two would vary, depending on the number 
and extent of the ravines within the circle. The mosquito 
attack on the centre might be likened to a series of columns 
invading along the lines of the ravines, rather than to a diffuse 
cloud of insects flowing in from every part of the periphery of 
the circle. If this were so, then it would follow that the area 
to be drained must be larger, the greater the number and 
acreage of the ravines within the circle and on its periphery ; 
and smaller under the opposite conditions ; but no mathematical 
formula correlating the two factors could be devised until 
practical experience of a completed scheme gave us some 
knowledge of a third factor — the malaria-carrying power of 
A. maculatus under such conditions. 

The information required was not merely how far A. 
maculatus could fly ; what was wanted was a knowledge of how 
far it could carry malaria. It was immaterial if some mosquitoes 
could fly or be blown one mile or ten miles from their breeding- 
place ; but it was important to know how far the insect could 
fly in such numbers that malaria would remain as an endemic 

L 



132 SEAFIELD ESTATE AND SUBSOIL DRAINAGE 




HmcrvWaikerLttl.se. 



FlG. 31. — Plan of Ravines of Seafield Estate, Southern Division. 



THE ENGINEERING PROBLEM 133 

disease. On the flat land the spleen rates were found to fall 
progressively, the further the children were from the jungle 
home of A. umbrosus ; until, at a distance of half a mile, the 
spleen rates were nil. Would the circle in the hill land require 
a radius of half a mile? A. umbrosus is a strong flier, and 
fierce biter ; it will attack at any time of the day in heavy 
shade, either in the jungle or in a house. A. maculatus is 
relatively a delicate mosquito, dying quickly in captivity, and 
rarely, if ever, attacking during the day. Would it fly as far 
as A. umbrosus ? That was a question we could not then 
definitely answer. 

Where so much was uncertain, it was decided to begin 
with a circle of about 20 to 25 chains, and if that led to 
improved health we could afterwards enlarge the circle until 
malaria had entirely disappeared. This procedure would not 
only be of assistance in determining exactly how large the circle 
must be ; but, on financial grounds, it was sound. To increase 
the radius of the circle from 20 to 40 chains was to quadruple 
the area, and would probably more than quadruple the costs ; 
for the farther the ravines run, the larger they become, and 
the more costly their subsoil drainage would be. Where the 
cost even of a small experiment was to be considerable, it was 
important to avoid unnecessary expense ; and, since proceeding 
by stages would give the maximum information with the 
minimum risk of wasting money, it was the policy I advised. 

The Engineering Problem. — Seafield Estate consists of a 
series of small hills, part of the granite upheaval. The granite 
outcrops at a number of points in the ravines ; but for the 
most part the rock is covered by deep, rich, friable red soil. In 
a number of ravines, however, the recently decomposed granite 
has become exposed ; and there the ground consists of a 
mixture of fine white clay, kaolinite from the felspar of the 
granite, infiltrated with grains of sand and particles of white 
gravel, the quartz of the granite. This white clay is practically 
impervious to water ; so springs and seepages are abundant in 
ravines which contain it ; and some Old Seafield ravines are 
largely like this. Where most of the white clay had been 
washed away, the sand and gravel were left in a mixture which 
has about as much stability as " porridge " ; that was how 
Mr Norman Grieve described it. 

Down these ravines torrents of tropical rain pour ; 



134 SE AFIELD ESTATE AND SUBSOIL DRAINAGE 

frequently one or two inches fall in an hour or less. Twenty 
inches might fall in a month; there might be twenty wet 
days in a month. In the steeper parts of the ravines, the 
once narrow drains had been scoured into wide, deep, un- 
even channels ; in the flatter parts, the drain was obliterated 
by the silt from above, and the whole ravine converted into 
a wide swamp. In such ravines, and under such conditions, 
the new system of subsoil drainage was to be tried. The 
ancients had employed subsoil drainage in agricultural land ; 
but the method of using it to control mosquitoes in hill 
streams and ravines, which I now proposed, was, as far as I 
am aware, new. The idea first came to me when reading 
Howard's account of malaria in Central Africa, in which he 
states that the cost of lime is £6 per ton, and of English 
cement, £17 per ton. On my arrival in England in 1908, I 
made inquiries into the method of agricultural drainage, and 
bought some books on the subject. On returning to Klang 
in October 1908, I discussed the subject with the Chairman 
of the Klang Sanitary Board, the late Mr J. Scott Mason, 
and Mr John Gibson, General Manager of the Tremelbye 
Rubber Company, who was familiar with subsoil drainage in 
Scotland. It was decided to try it on one of the hill-foot 
drains in Klang. A Chinese roof tile maker was approached, 
and after several attempts he succeeded in turning out about 
fifty very respectable-looking tiles, and agreed to make more 
at a cost of two cents each. These were the first subsoil 
agricultural pipes made for anti-malaria work in the F.M.S. 

Then appeared Mr Sime's paper in the Liverpool Annals 
of Tropical Medicine, from which it appeared that a system of 
subsoil drainage had been adopted in Panama with success 
some two years before. Although it differed in some important 
points from what I proposed, we decided to take no further 
action in Klang at the moment, as the special problem in 
hill land had come into view. 

When convinced that A. maculatus in hill land could not 
be controlled by ordinary agricultural methods, I turned to 
the idea of drying the beds of the ravines by a system of 
subsoil drainage. It seemed likely, too, that by this drainage 
silt would be retained in the upper portion of the ravines, and 
would not cover the outlets of the subsoil drainage system in 
the lower portions. The ravine soil, consisting of porous silt 




Fig. 32. — Seafield Estate. 
The condition of the upper portion of Ravine " A " before subsoil drainage. 




Fig. 33. — Seafield Estate. 
The Ravine of Fig. 32 when first piped. 



[To face page 1 34. 



THE ENGINEERING PROBLEM 135 

and gravel, was to cover the pipes to a depth of three or 
more feet ; it would allow seepage water, and some of the 
storm water to pass through it to the pipes, but would, so 
to speak, filter out any silt descending from the higher land, 
and retain it on its surface. The depth of the soil over the 
pipes would gradually be increased, but that would be no 
disadvantage. The deeper the soil over the pipes, the 
deeper the dangerous seepage and springs would be buried, 
and the less chance would there be of storms scouring out 
the pipes. 

The powerful erosive action of storm water also required 
consideration. The pipes could be buried under a heavy layer 
of stone of graduated size with the smallest on the top. But 
it appeared to me essential, if we were to keep the silt from 
reaching the pipes in quantity and blocking them, that nothing 
less than a fine filtering layer composed of silt itself must be 
the top layer : and if the top layer, which would bear the brunt 
of the storm waters' action, must be a fine soil, stones under 
it would not be required from an engineering point of view, 
and so would be unnecessary and expensive. 

It was, therefore, decided not to lay stones over the pipes, 
but to break the power of the water by widening the storm water 
channel. This method differs from that employed in Panama, 
where earth is not put over the stone. " The dirt from the trench 
must be placed on the down-hill side of the line, to prevent it 
washing back into the ditch. When the soil uphill from the 
ditch is covered with vegetation, the space between the cover 
stones does not fill up" — so Mr W. Prince describes his method. 
When in Panama, I found that the soil was not friable or sandy 
like that in the F.M.S. The Panama system, although suited 
to that country, is quite unsuited to ravines in the F.M.S. ; 
indeed, a modification of it was tried in Kuala Lumpur and 
proved a failure as we shall see. 

A system of open concrete drains in our ravines would have 
been useless. They would have been scoured out in the steeper 
portions of the ravines, and silted up in the lower. In Kuala 
Lumpur they were tried, and failed for these reasons (Fig. 35). 

The Scheme approved by the Directors. — From 1905 to 1908 
the ravines on Seafield Estate had been kept free from all 
grass and vegetation with the idea of eliminating A. maculatus. 
Mr H. R. Quartley took the keenest personal interest in the 



136 SEAFIELD ESTATE AND SUBSOIL DRAINAGE 

matter ; and the failure to eliminate the mosquito was not for 
lack of care. Nor had quinine been given to the labour force 
in any perfunctory way. Mr Quartley realised that the success 
of the estate depended on a healthy labour force, and anything 
he undertook to do to improve the health was done thoroughly. 
Quinine was given at the muster, and no coolie received "a 
name " for his day's work until he had swallowed the quinine. 
We saw the health improve, and the death rate come down : 
but a healthy labour force could not be built up. All new 
comers suffered from malaria ; only a small proportion became 
immune ; the others left the estate or died. The failure of 
quinine to eliminate the disease was definitely established, 
and accepted by Mr Quartley and myself in 1909; nothing 
more could be expected from clean weeding the ravines; 
nor would anything have been gained by abandoning them 
to revert to jungle. Our only hope appeared to lie in 
subsoil drainage ; we discussed this. It appealed to Mr 
Quartley ; and he placed it before the directors, giving it his 
strongest support. He pointed out how it had been impossible 
to build up a healthy labour force ; how, despite everything 
that could be done, the death rate of the labourers was so high 
that it could not be allowed to continue ; how Europeans as 
well as Asiatics suffered, and proper supervision of estate work 
was difficult, if not impossible ; and that if the estate could be 
made healthy at any reasonable cost, the expenditure would 
soon repay itself. Owing to his urgent representations, the 
directors deputed one of their number, Mr Norman W. Grieve, 
to visit the estate and decide whether or not to proceed with 
the scheme. Pending his arrival, Mr I. Irvine, M.I.C.E., in 
1910 made a survey of the ravines, and prepared plans and 
estimates. In 1910, at a meeting held at Seafield Estate, 
Mr Grieve, on behalf of the Board of Directors,* sanctioned 
the scheme. Mr Bach, M.I.C.E., was engaged to carry out 
the work. He arranged for a Chinese roof tile maker to 
make the pipes; and the first pipes were laid on 1st June 191 1 
on Old Seafield. 

A. maculatus as a Natural Carrier of Malaria confirmed. 
— The announcement that A. maculatus would not disappear 
without special measures to exterminate it, and that unless 

* The Board of Directors consisted of H. K. Rutherford, Esq., Chairman ; 
Joseph Fraser, Esq., Norman W. Grieve, Esq., John M'Ewan, Esq. 












Fig. 34 — Seafiei.h Estate. 
The Ravine of Fig. 32 when finished. 





Fig. 35. 
An open cement channel in Kuala Lumpur which had to be 
replaced in the steeper portions of the ravine because of the soil 
erosion. Such a channel as this could be put down in Panama 
without aay such risk. 



V 



[To face page 136. 



A. MACULATUS A CARRIER OF DISEASE 137 

measures were taken hill areas would remain permanently 
intensely malarious, naturally caused anxiety to the planting 
community. Hitherto the hills had been regarded as a refuge 
from malaria whose home was supposed to be swamps and 
flat land, especially near to the coast. So it was in Italy, from 
which country most of our ideas of malaria had come. But 
in Malaya my observations had cut away all ground for hope of 
improvement in the hill-land estates, and I received numerous 
letters on the subject. 

The Directors of Seafield Estate had decided to proceed 
with the work on my advice, but I felt it would be more 
satisfactory to them if my findings were confirmed by a 
competent scientific observer. Accordingly I asked Dr A. T. 
Stanton, of the Institute for Medical Research, if he would 
be good enough to visit Seafield Estate to check my observa- 
tions ; and, if he confirmed them, to give me a letter which I 
could send to the Directors of Seafield Estate, and to any 
other companies that might be interested. This Dr Stanton 
kindly consented to do ; he visited the estate, and sent me 
the following letter : — 

" Very many thanks for your courtesy in giving me an 
opportunity to test the accuracy of your observations with 
reference to the malaria-carrying mosquitoes of hill estates. 

" As I have already written, I was able to confirm the 
finding of zygotes in the stomach wall of N. willmori by the 
examinations of specimens taken in Kuala Lumpur, and our 
finding of sporozoites in the salivary glands of specimens taken 
in the coolie lines of a hill estate proves the accuracy of your 
original observation that this species is a carrier in nature. 

" The number of N. willmori taken in the lines, and the 
readiness with which we were able to demonstrate the parasite 
in them during a period, when, as the manager informed us, 
the estate was comparatively free from malaria, is ample 
evidence of the importance of this species in the spread of 
malaria in hill areas. 

" I was greatly interested in your demonstration of the 
breeding-places to which you refer in your book. My own 
more limited experience of the breeding-places of anophelines 
would have led me to doubt the likelihood of finding larvae 
attached to small stones in a stream of considerable volume 
and current free from grass and other vegetation. The fact 
that we did find them in those situations as well as in large 
numbers in small pools in sand at the side of the streams shows 



138 SEAFIELD ESTATE AND SUBSOIL DRAINAGE 

the very great difficulty likely to be experienced in freeing 
these areas of malaria. 

" I hope you will be successful in the measures you have 
proposed, and I may perhaps be permitted to congratulate 
you again upon the very important additions you have made 
to our knowledge of malaria, the most important disease 
problem, as I believe, which confronts sanitarians in this 
country. — Yours sincerely, A. T. Stanton. 

"Institute for Medical Research, 
"Kuala Lumpur, 27 tk June 191 1." 

Progress of the Work — Old Seafield, or Southern Division. — 
The first ravine drained was one of the steepest, and its soil 
specially friable. What appeared to be an ample storm-water 
channel was made ; and for several months the work remained 
intact despite considerable rains. But during the very heavy 
and continuous rains of December scouring occurred, and it 
was evident that a wider channel was required. 

With characteristic thoroughness Mr Quartley decided to 
provide the maximum security for the pipes ; he swept away 
all rubber trees 1 from, " filled in," and "barrelled" the bottom 
of the ravine ; so that the stream water no longer acted chiefly 
on the line of the pipes. It was spread over the whole ravine, 
and rather on the sides than the centre. 

By April 191 2 such progress had been made that all ravines 
within 25 to 28 chains of the coolie lines had been drained. 
It did not, however, include the large ravine, B. The area 
was not completely free from breeding-places ; wherever white 
clay had been exposed seepage water poured out, until secondary 
lines of pipes finally cut it off. Some wells also remained in 
connection with the water-supply. As all the engineering 
problems had been solved, and already the health of the labour 
force had improved, it was decided to extend the area to 
40 chains from the lines. 

(191 3). — The new area taken in consisted of the lower and 
flatter portions of the ravines, and, although an increased 
sectional area of pipes was laid down, it proved insufficient 
to discharge the water quickly enough in the wet weather 
at the end of the year. Water, therefore, appeared on the 
surface of the upper parts of the ravines, which had been dry 
in 1912, just as if drains were blocked. One of the dis- 
advantages under which the estate worked was the impossibility 




Fig. 36. — Subsoil Drainage. 
Finishing off the day's work with timber to prevent damage from rain during the night. 




Fig. 37. — Subsoil Drainage. 
A "Wash-out. 



[To face page 138. 



NEW SEAFIELD, OR NORTHERN DIVISION 139 

of calculating the sectional area of the pipes required to drain 
a ravine. No pipes larger than 8 inches in diameter were 
obtainable ; and it was only by observing the results in wet 
weather that the right number of lines of pipes could be 
determined. 

In 1914 two additional lines of pipes were laid down in 
Ravines C and D; and in 191 5 in Ravines A and B. So 
that it was the end of 191 5* before Old Seafield had the 
advantage of drainage area of a 40-chain radius, everywhere 
except in one direction, namely, in Ravines E and F. 

New Seafield, or Northern Division. — In January 1914 work 
was begun on the New Seafield Division, and. by the end of the 
year had been carried out for 26 chains in one direction and 
16 chains in the other. The whole area was completed by 
the end of 191 5. Profiting by the experience gained on Old 
Seafield, the sectional area of the pipes was ample, and the 
ravines have been dry since they were drained. 

All wells were closed as soon as the pipe water-supply was 
laid on in 191 3 ; as A. maculatus and A. umbrosus breed in 
them. It was necessary, however, to keep the main water-supply, 
which comes from a reservoir in a branch of the head of ravine 
A, situated close to the coolie lines and two bungalows on 
Old Seafield. From time to time larvae would be taken in 
this water ; but so seldom as to appear negligible. Alga 
grew on the bottom of the reservoir ; in dry weather portions 
died off and floated to the surface. To ascertain to what 
extent this reservoir was a breeding-place, about a quarter 
of the floating debris was skimmed off, placed in a large jar, 
and treated with a strong solution of copper sulphate. The 
alga quickly shrivelled and sank to the bottom, leaving only 
small fragments of twigs and leaves. On searching this care- 
fully, forty-nine larvae were found, of which thirty-six were 
A. sinensis (which I do not regard as an important carrier of 
malaria) ; ten were A. umbrosus ; and three were so small 
that they could not be identified with certainty, but were 
probably A. umbrosus. 

In view of this observation, it seemed advisable to control 
the reservoir as a breeding-place. Oil could not be applied ; 
but copper sulphate is added each week, and has greatly 
diminished, although it has not entirely killed out the sign. 
* One ravine still gives trouble (1920). — M. W. 



CHAPTER XIV 



SEAFIELD ESTATE {continued) 

The Medical Results from the Drainage. — The drainage was 
begun in June 191 1, and was completed at the end of 191 5. 
The estate, of course, benefited from each acre of breeding- 
place abolished, but the full benefit from the work was obviously 
not to be obtained for some time later. How much the health 
did improve will be seen from the following table : — 



Year. 


Average 


Death Rate 


Year. 


Average 


Death Rate 


Labour Force. 


per 1000. 


Labour Force. 


per 1000. 


1906 


175 


II 4 


1913 


552 


IIO 


1907 


380 


63 


1914 


658 


69 


1908 


399 


30 


1915 


804 


48 


1909 


345 


52 


1916 


811 


43 


1910 


426 


133 


1917 


770 


36 


1911* 


520 


144 


1918 


693 


7 St 


1912 


427 


I 2 3 


1919 


825 


37 



Drainage begun. 



t Influenza. 



On 31st December 1919, there were no fewer than 998 workers, 
and 143 dependants, that is children and old people who do 
not work. The table shows a fall in death rate, interrupted 
only by the influenza epidemic of 191 8, and its continuation 
in 1919 (see Chapter XXIX.). From it we can calculate 
roughly the number of lives saved in the last six years. Before 
doing so, however, I must point out that a labour force of over 
600 coolies could not have been maintained unless the drainage 
had been carried out. On Seafield Estate, as on others in 
Malaya, labour is free, no indentured labour is allowed ; no 
labourer can sign a contract. He comes of his own accord, 
usually on the recommendation of relatives living on the 
estate ; he is free to leave on giving a month's notice or 
paying a month's wages. In practice he often leaves after 

140 




Fig. 38.— Subsoil Drainage. 
Water showing on the surface of a ravine when the pipes are blocked. 




Fig. 39. — Seafield Estate. 
Ravine " A " during a tropical shower, after subsoil drainage. 



[To face page 140. 



MEDICAL RESULTS FROM THE DRAINAGE 141 

pay day, without notice or payment in lieu of notice. When 
an estate has a reputation for being malarious, it has difficulty 
in obtaining labour. Were it possible to pour labour into such 




)•'. mery Walker Ltd. sc, 

FIG. 40. — Plan of Ravines of Seafield Estate, Northern Division. 

a place as Seafield was in 191 1, so as to maintain an average 
labour force of 600 coolies, the death rate would be little 
short of 300 per mille per annum (see Chapter XI.). In the 



142 SE AFIELD ESTATE AND SUBSOIL DRAINAGE 

year 1908 there were in the F.M.S. twenty-one estates (eighteen 
of them in hill land) death rate of which was over 200 per mille. 
An adjoining estate, and one not usually regarded as so 
malarious as Seafield, had death rates between 1906 and 1910 
as follows: — 146, 157, 176, in, 152 ; and in 1908 the average 
death rate of the Batu Tiga District in which Seafield is 
situated was 140 per mille. 

In our calculation of the number of lives saved, we may 
safely take 144, the death rate for 191 1, as the base line; 
confident that it is an underestimate. Figures are as follows : — 



Year. 


No. of Deaths at 
144 per mille. 


No. of Deaths 
actually occurred. 


No. of'Lives 
Saved. 


1914 

1915 
1916 
1917 
1918 
1919 

Total . 


94 
115 
116 
109 

99 
"3 


48 
39 
35 
28 

52 
31 


46 
76 
81 
81 

47 
82 


646 


233 


413 



This calculation indicates that labourers equivalent to over 
one half of the present labour force have been saved during 
the past six years. 

The reputation of the estate for health is now such that 
coolies come to it freely from India ; indeed the year 1919 
tested the health conditions severely ; for no fewer than 957 new 
coolies arrived from India, most of them below the average 
in health, and large numbers suffering from influenza and its 
consequences. Not only had the rice famine affected them in 
India, but on the estate they were on short rice rations, 
supplemented by other foodstuffs, with the cooking of which 
they were unfamiliar. To this is attributable the increase of 
bowel diseases ; for the digestive organs of the Tamil cannot 
be experimented on with impunity. Influenza, complicated with 
pneumonia, which apparently had existed since 191 5, and reached 
its zenith in the epidemic of 1918, still haunts the immigrant 
ships. In the quarantine camp at Port Swettenham in 19191 
no less than 5757 cases of influenza occurred ; and there were 
839 cases of pneumonia with 356 deaths. 

Under these circumstances it is not surprising that in the 




[To face page 142. 



SPLEEN RATES AND THE CHILDREN 143 

last four months of the year influenza was epidemic in 
prevalence on the estate, although not in the severe form of 
1918. There was also a slight increase in the incidence of 
malaria in the last few months of the year, causing three deaths ; 
but for the first time in the history of the estate the great 
wave of malaria, which begins about April, did not occur on 
New Seafield. While it is evident malaria is still being 
propagated, it is satisfactory to note it is decreasing. We can, 
1 think, look forward confidently to still further improve- 
ment, and to a death rate not exceeding 10 per mille ; 
for if the death rate of uncontrolled malaria runs up to 300 
per mille, there is abundant evidence that, where malaria is 
absent, the death rate of Indian labour forces in this country 
need not exceed 10 per mille. 

Spleen Rates and the Children. — In the last paragraph of 
the first edition of this book, I commented on the relation 
between malaria and the labour problem, and said further : 
" No estate can ever have an assured labour force where the 
women wail, ' We cannot have children here, and the children 
we bring with us die.'" Such is the cry on the unhealthy 
estates. It is in vain to contend with her " who weeps for her 
children and will not be comforted." 

Seafield was such a place a few years ago. Those who 
have not seen the barrenness of an intensely malarious estate 
will find it difficult to picture the conditions. In Chapter XI. 
Mr Carey tells how in six years no Tamil child was born 
alive on New Amherst Estate. On 26th October 1909 I noted : 
" In three years five children have been born on New Seafield, 
of whom two have died ; only three children born on Old 
Seafield, all died. Three children were conceived on the 
estate." Pregnant women had come from India; malaria had 
usually caused miscarriage. But on the estate itself only three 
children had been conceived. 

There is no complete record of all the children who died 
on the estate in the early years ; it would have been sad 
reading. One of my earliest recollections is of a child being 
brought to me at Klang with greatly enlarged spleen. He 
rapidly improved on an ordinary mixture of quinine sulphate ; 
and for months the parents sent to Klang for the medicine, 
although the identical mixture was made up on the estate, 
The boy was the only child of M , the head kangany (or 



144 SEAFIELD ESTATE AND SUBSOIL DRAINAGE 

native overseer) ; he was given the quinine for years, in fact 
until he left for India in 191 1. The story ends in tragedy- 
All through the malarious years, from 1905 to 191 1, M , his 

wife, and the child kept alive. These had no other children ; 
but in 191 1 the woman became pregnant; great anaemia 
followed ; an attack of malaria brought on labour, perhaps a 
little premature. Twins were born. They and the mother 
died within twenty-four hours. It has always seemed to me 
a cruel fate that, after struggling through all the malarious 
years, she should have died just when we had begun the 
measures which were to control the disease. After his wife's 

death, M seemed to lose heart, and went to India, promising 

to return with more coolies. But he had seen his wife and so 
many of his friends and relatives buried on the estate that he 
did not return ; and there was reason to suppose he stopped 
coolies from coming over. If he did, who shall blame him ? 
I believe the boy lived. 

To-day the story is very different; although the change 
came gradually. On 23rd January 1917 on Old Seafield there 
were fourteen children without enlarged spleen who had been 
over six months on the estate ; on New Seafield there were 
nineteen. On 18th January 1918 there were eighty-three 
children, of whom twenty had been born on the estate ; not 
one of the twenty had enlarged spleen. In 1917 thirteen 
children were born on the estate ; in the two succeeding years 
the numbers were seventeen and twenty-five. 

Spleen Rates. 



Year. 


Old Seafield. 


New Seafield. 


Number 
Examined. 


Spleen Kates. 


Number 
Examined. 


Spleen Rates. 


1905 
1906 
1909 
1914 

1915 

1916 
1917 
1918 
1919 


16 

17 
II 
20 

12 

34 

32 

52 

107 


68 
88 
Si 
50 
83 
85 
28 

7 
21 


36 
39 
30 
37 
36 
31 
59 


58 
76 
60 

73 
47 
41 
30 



In 1918 I recorded that although the spleen rate of New 
Seafield was still high, in more than half of the children 




Fig. 42.— Seafield Estate. 

The end of the subsoil pipes in Ravine " A." From this point the water continues 
in an open drain. Photograph taken in dry weather. 



[To face page 144. 








.:'•.'. 



■ 



* O 



(To face jiaje 144. 



SPLEEN RATES AND THE CHILDREN 



145 



the enlarged spleen was so small that it was just palpable. 
Of course it takes some time for chronically enlarged spleens 
to disappear — often three and four years ; so it was of interest 
to note the spleen gradually going. I added, " To me the 
most gratifying sight of my last inspection of the labour force 
was, not so much the large number of healthy coolies, as 





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140 






























tu 


130 














S 


EAFIE 


LE 


i ESTATE 


5 


120 






























3 
O 


110 






























1000 


100 






























900 


290 






























800 


|eo 




























/ 


700 


O70 




























/ 


v 


600 


n60 
































500 


50 
















/* 


£ 












400 


40 














v 


f 












300 


30 
































200 


20 






























100 



10 






























































Fig. 44. — Chart of the Death Rate of Seafield Estate. 



the number of mothers with the healthiest babies imaginable 
in their arms." 

In January 1920 on Old Seafield in 18 of the 23 children 
with enlarged spleen, the organ was just palpable, and one 
child was a healthy infant twenty days old ; 48 children with 
normal spleens had been over six months on the estate. 

On New Seafield there were five spleens of considerable 
size; the others were just palpable. Of the 41 children with 
normal spleens, 24 had been over six months on the estate. 



146 SEAFIELD ESTATE AND SUBSOIL DRAINAGE 

From these figures it is evident malaria is still being 
contracted on the estate ; but it is becoming less intense as 
it decreases in amount. 

To sum up, what was probably as intensely a malarious 
place as exists on the face of the earth, one which for the 
Indian labourer was uninhabitable except at an unjustifiable 
cost of life, is now so free from malaria, although not completely 
free, that Indians come to it readily, a large and efficient 
Indian labour force lives on it, and a further reduction in 
malaria and a further improvement in health may be antici- 
pated with confidence. 



CHAPTER XV 

SEAFIELD ESTATE {continued) 

The Financial Results of the Drainage. — To determine accurately 
in dollars and cents the total value to Seafield Estate of the 
subsoil drainage is a matter of considerable difficulty. Some 
items can be accurately assessed ; on others it is difficult to 
put a figure. In order that the financial aspect of the work 
may be understood, it will be necessary to explain the labour 
problem of estates in this country. 

Indian Labour. — In the F.M.S. planters desire to establish 
on their estates an Indian labour force. In part this is due 
to tradition ; for the pioneer planters of Malaya came from 
Ceylon, where Indians, and more particularly Tamils from 
Southern India, were employed on the coffee and tea estates. 
The habits and customs of Tamils were understood, their 
language spoken by the planters ; so it was natural that 
when coming to Malaya, where no indigenous labour was 
available, and some labour foreign to the country must be 
introduced, Tamils were selected. As a labourer the Tamil 
is quiet and reliable when justly treated ; and from a few 
hundreds, the Tamil population has increased to tens of 
thousands. 

To the Indian coolie, who comes here, the F.M.S. 
is an El Dorado in comparison with his native country ; 
there he belongs to the lowest castes or " depressed " classes. 
In years of a "bad monsoon" and famine, starvation is his 
lot ; years of prosperity give him a bare living. He comes 
to this country, as a rule, in poor physical condition, penniless, 
and in rags. A year on a healthy estate, with good wages 
and good food, improves him and his children beyond 
recognition. Not only is he well covered with clothes and 
flesh, and looks healthy ; but he becomes relatively wealthy. 
Until last year he could live well on less than half his 

147 M 



148 SEAFIELD ESTATE AND SUBSOIL DRAINAGE 

earnings, and the balance he could remit to his relatives 
in India at such a favourable rate of exchange that it 
often amounted in India to as much in rupees as he could 
have earned had he remained there. Through the Post Office 
are sent large sums annually ; and even larger amounts 
are carried over personally. The immigration figures show 
that the coolie usually returns to India in two years ; that 
means he has saved enough to do so. The employment 
of Indian labour at the wages earned on estates is, therefore, 
advantageous both to the Indian and the estate. 

The system by which he is introduced to the country 
is comparatively simple. Some coolie on an estate in Malaya 
has friends or relatives in India who, he thinks, would 
come to the estate; so he is given a "licence" to "recruit" 
by the Labour Department — a department of Government 
which concerns itself with the welfare of the labourer. 
Armed with the " recruiting licence " the coolie visits his 
village, and if successful, brings over a few other coolies. 
These coolies receive a free passage from a fund raised by 
assessing all employers of Indian labour, and arrive on 
the estate free from debt. There is no "indentured labour" 
in British Malaya; no coolie may sign a contract to labour; 
he is at liberty to leave on giving a month's notice, or at 
once on giving a month's pay ; in practice, as I have said 
before, he often leaves without giving either. 

By law he must be provided with free housing accommo- 
dation, free medical and hospital treatment ; and regulations 
of many kinds for his welfare are strictly enforced by the 
department referred to above. Where the death rate of 
an estate is high, the employer may be prohibited from 
employing Indian labour. In the early years of the industry, 
this rule was not strictly adhered to ; for malaria and ill-health 
were regarded as inevitable in the opening of a new country and 
as a passing phase. But as the causes of ill-health have come 
to be better understood, and its prevention placed on a 
practical footing, the regulations are now very strictly 
interpreted and enforced. 

So Indian labour is preferred because the coolie and 
his language are understood by planters, and because it 
is reliable when healthy. At the same time, there is con- 
siderable expense in recruiting it, in transporting it from 



CHINESE LABOUR 149 

India, and for medical treatment on the estate, especially 
when the estate is unhealthy. Indeed, if the estate be very 
malarious, the Indian requires higher wages, does poor work, 
is an indifferent, undesirable labourer, and ceases to be an 
asset. 

Where an estate is very malarious, and the death rate is 
high, the Indian Government prohibits the employment of 
the Indian labourer. 

Chinese Labour. — His place is taken by the Chinese, to 
whom Malaya owes so much. Long before the British 
administration was established in these parts, Chinese were 
working the rich tin land of the Peninsula. They come 
from a land where the seasonal variations give a period of 
comparatively, if not absolutely, cold weather, and are a virile 
race, full of enterprise and energy, well able to hold their 
own against any other race in the East ; and probably, for 
that matter, against many in the West. Patient and efficient 
labourers ; yet, for the European, difficult to work. This arises 
mainly from the fact that the language presents an almost 
insuperable obstacle to direct communication between the 
labourer and his Western employer. Language ! — it would be 
more correct to say languages. Although there is one 
ideographic writing common to the Chinese Empire, the 
dialects differ so much that Chinese from the several provinces 
cannot understand each other. In Malaya, the labourers speak 
many dialects ; each one of which requires several years of 
study before even a smattering is acquired by the average 
European ; and until the European changes his mental equip- 
ment or the Chinese his language, there is little chance of 
direct communication between the planter and the labourer. 
The difficulty is overcome by the planter engaging and super- 
vising his labour through a "contractor," a Chinese who speaks 
either English or Malay — the lingua-franca of the Archipelago. 
Through him the employer arranges the terms of the contract ; 
to him the planter gives directions ; and he is held responsible 
for the proper execution of the work. 

On an unhealthy estate, Chinese, like Indians, suffer from 
malaria and its accompanying diseases. He has no natural 
immunity. On occasions I have seen him as badly stricken 
by the disease as Indians ; Port Swettenham in 1901 is an 
example. Chinese have little faith in Western medicine, and 



150 SEAFIELD ESTATE AND SUBSOIL DRAINAGE 

do not usually seek admission to an estate hospital. When 
ill, the coolie prefers to leave the estate and go to his friends 
elsewhere. There he is treated according to " Chinese 
fashion " : when well, he returns to the estate ; if he dies, his 
friends bury him, and the estate manager probably hears 
nothing of it. Leaving the estate gives him a better chance 
of recovery than if he remained there subject to constant 
re-infection ; and we find that a large percentage of Chinese 
on unhealthy estates have enlarged spleen, showing they have 
recently acquired or are acquiring a natural immunity. Two 
other things are in his favour : he believes in the mosquito 
net — practically every coolie uses one ; and he feeds himself 
much better than the Indian. So it comes about that Chinese 
live and work on places where Indians die off rapidly and 
where the planter's hope of establishing an Indian labour 

force — 

" Like Snow upon the Desert's dusty Face, 
Lighting a little hour or two — is gone." 

If a Chinese coolie takes the risk of an unhealthy estate, 
he expects to be well paid for it. He is no philanthropist; 
on the contrary, he is fully convinced that the labourer is 
worthy of his hire — and sees that he gets it. Centuries of 
oppression in the Flowery Land have taught him the art of 
combination. His Societies and Guilds — practically every 
Chinese of the lower classes belongs to one — are so highly 
organised that a Western Trade Union could teach him 
nothing ; and probably could learn a good deal. He is, 
therefore, practically in a position to make his own terms; 
and they are a long way above what the Tamil considers 
affluence, and flocks from India to obtain. In short, while 
with Tamil labour it costs on an average about 7 cents a 
pound to tap and collect rubber, Chinese tapping costs 14 
cents. So Tamil labour saves, say, 7 cents a pound, and on 
a crop of 1,000,000 pounds in a year, the gross saving is from 
$70,000. This places a high premium on health; and, apart 
from any other consideration, has been a material stimulus 
to estate sanitation. 

Bark Renewal. — I have said that the Chinese are " patient 
and efficient labourers." Unfortunately this is often not true ; 
and particularly when labour is scarce. Good Tamil or Chinese 
tappers do not remove more than one inch of bark each 



TAMIL LABOUR 151 

month, sometimes less. Rubber latex comes from the bark, 
which thus forms the capital of the estate. The renewal of 
bark requires time, and systems of tapping are arranged so 
as to give four or six years' renewal, before the same part of 
the tree trunk is tapped again. Bad or careless tappers not 
only remove two or more inches of bark each month, but cut 
so deeply that the cambium is wounded ; scars form in the new 
bark ; where there are many scars, tapping over the renewed 
bark may become almost impossible. There are widespread 
complaints from estates compelled to employ Chinese of the 
quantity of bark used and wounds made, and of the inability 
of the management to effect improvement as long as the 
only labour possible is Chinese ; and there is a shortage even 
of that. It will be apparent from this that the cost to an 
estate of Chinese tapping is not merely the 7 or 8 cents a 
pound that it is over the Tamil cost; the loss of double 
the amount of bark is of even more consequence, since it may 
throw an area out of tapping for several years. 

Advantages and Disadvantages of Tamil Labour. — Tamil 
labour, however, is not without certain disadvantages which 
must be set against the cheap cost of tapping. 

As far as Seafield Estate is concerned, the high death rate 
would have led to an order prohibiting the employment of 
Indians ; even had some Indian labour been allowed, it would 
probably not have been sufficient in numbers, or reliable 
enough in " out-turn," to tap the trees ; all tapping would 
have been done by Chinese. 

It is now time to detail, if not to assess, the value of the 
items in the account, and I will begin with the 

Disadvantages. — (1) Indian labour has involved heavier 
medical charges. In 1919 these were $15,061. 

(2) The total capital cost of the pipe drainage, 1911-1918, 
was $68,243. 

(3) The upkeep of ravines, including oiling in 1919, was 
$11,013. 

(4) To lay the system many rubber trees were cut out, 
reducing the rubber crop ; this would probably have been 
an annually diminishing amount, as some of the ravines 
would probably have become silted up, and the trees would 
have died out. 

(5) Cost of recruiting Indian labour. 



152 SEAFIELD ESTATE AND SUBSOIL DRAINAGE 

(6) Assessment on Indian labour. 

(7) Loss on selling rice below cost price. 

(8) Loss on Exchange — remitting money to India above 
the market rate. 

Advantages. — (1) The improved health of the Europeans has 
(a) reduced their hospital charges ; (&) reduced the sick leave ; 
(c) improved the supervision of work, particularly of the con- 
servation of the bark — an important item. 

(2) Abolished the cost of upkeep of open drains in the 
ravines — a considerable item on account of silting. 

(3) Reduced the cost of tapping by the gradual substitution 
of Tamil for Chinese labour. 

(4) The last of the Chinese left in November 1919; but 
subsequent to 1914, when the percentage of the total crop har- 
vested by the Tamils had increased from 49 to 89, the improved 
health of the estate, and the competition from the Tamils, 
induced the Chinese to work at a rate considerably below 
the average for unhealthy estates. Before they left, the cost 
of Chinese tapping on Seafield was 831 cents per pound against 
an average of over 14 on unhealthy estates. 

(5) There are certain advantages from the employment 
of Tamils in estate work generally, particularly in weeding. 
Under mature rubber, from four years old upwards, the 
shade is heavy and few weeds grow. But in younger rubber, 
weeding is probably the most important work. If land is 
weeded regularly every two or three weeks — that is before the 
weeds can produce a crop of seed — the cost of weeding may be 
brought down to well under one dollar an acre per month ; but 
if neglected for three months, it may cost seventy-five dollars 
or more an acre to clean up, and a heavy monthly expenditure 
afterwards, as I have explained in a previous chapter. 

The best, and in the end cheapest, weeding is done by 
hand ; each weed being picked out of the ground and removed 
in a bag. This the Chinese will not do ; the Tamils will. 
So during the years when the fields are young, a Tamil 
labour force is an asset of great value. Even when an estate 
is unhealthy and Chinese are employed for tapping, every 
endeavour is made to maintain a small gang of Tamils to 
weed the younger fields, and do similar estate work. 

Cost of Production of Rubber. — After many discussions 
with those familiar with the subject, it appeared that the 



COST OF PRODUCTION OF RUBBER 



153 



only satisfactory way to estimate the value to Seafield Estate 
of a Tamil labour force would be to compare its f.o.b. cost 
of production with that of other estates employing Chinese 
labour, and to ascertain which was the cheaper. Inquiries 
were therefore made for an estate identical in acreage and 
yield with Seafield, but unhealthy and employing Chinese 
labour. As I was unsuccessful in finding one strictly com- 
parable in all respects, I decided to ascertain the average 
cost on a number of estates employing Tamil labour, and 
to compare that figure with the average cost of estates with 
other labour. Messrs Cumberbatch & Co., Ltd., Messrs 
Harrison & Crossfield, Ltd., Messrs Guthrie & Co., Ltd., Messrs 
Barlow & Co., Messrs A. C. Harper & Co., Ltd., Messrs Barker 
& Co., Ltd., and the managers of several estates courteously 
supplied me with the details of estates with a total of over 
71,000 acres in bearing, and from these I have worked out 
the average yield and cost. All are on hill land ; they fall 
into three groups. For obvious reasons I am not permitted 
to give further details. 

Group A, with 70 per cent, or more of the labour force 
Tamil. With one or two exceptions, all were intensely 
malarious, and but for the control of malaria would not 
now have a Tamil labour force. On several, further improve- 
ment in health is to be anticipated. 

Group B have a mixed Tamil and Chinese labour force. 
On some there is a considerable expenditure on anti-malarial 
work, but a full Tamil labour force has not been built up. 
The health of this group generally is unsatisfactory, but there 
are exceptions. 

Gi-oup C. Estates with 70 per cent, or more of the labour 
Chinese. Usually so unhealthy that Tamils cannot be 
employed. As a rule little is spent on anti-malarial work. 

The following table shows the total area in tapping in 
each group ; the average yield per acre ; and the average 
f.o.b. cost per pound in cents : — 





Group A. 


Group B. 


Group C. 


Average yield per acre in lbs. . 
Average f.o.b. cost per lb. in cents . 


ludians. 

431-01 
28-25 


Mixed. 

22,120 

367.40 

37-45 


Chinese. 

20,043 

400-30 

36.03 



154 SEAFIELD ESTATE AND SUBSOIL DRAINAGE 

Cost of Production with a Tamil Labour Force. — The 
average f.o.b. for Group C is 7-78 cents higher than for 
Group A, or roughly 30 per cent. In 19 19 the f.o.b. cost 
on Seafield was 24-17 cents, or u-86 cents less than the 
average f.o.b. cost of Group C, the Chinese worked estates. 
The saving on the whole of the Seafield crop is, therefore, 
11-86x1,147,553, or $136,099. 

Assuming, however, that Seafield was an average estate 
in Group A with the average saving of 778 cents — then 
the gross saving still amounts to $89,279, or over £10,000 
sterling. The capital cost of the subsoil drainage 1911-18 
was $68,243 — so that it was more than repaid in one year. 

However we look at the matter, it would appear that 
the whole cost of the subsoil drainage was repaid and probably 
much more than repaid in the year 1919; and that the gain 
in previous years, while less in amount, can have been no mean 
sum. In other words, apart from the saving of human life 
and conservation of " bark," the cost of the subsoil drainage 
has probably been repaid several times over in the past 
five years. 

Cost of Production with Mixed Labour Forces. — It is to be 
noted, and is significant, that on Estate No. 28, the cheapest 
producer in Class C (f.o.b., 29-78 cents), much is being spent 
on improving the health both by subsoil drainage and oiling ; 
and its figure of costs may be compared with Estates No. 27 
(f.o.b., 30-25 cents) and No. 22 (f.o.b., 26-60 cents) in Group 
B., on both of which also the health has been greatly improved, 
although labour forces exclusively Tamil have not yet been 
established. The higher cost of production of Group B as 
a whole, and its significant exceptions in comparison with 
Group C, would appear to indicate that there is a point 
in descending the scale of health, below which no advantage 
is to be gained from employing Tamils. It is, indeed, 
well recognised that, when an estate is unhealthy, Tamils 
cease to be an asset ; and it is not uninteresting that these 
figures should bear out that opinion. 

Cost of Production with Chinese Labour Forces. — Before 
passing, do not the figures for Estates No. 22, 27, and 28 
suggest the thought that Chinese can work better and therefore 
cheaper where they are healthy; and that it would pay, 
even where a Tamil labour force is not aimed at, to make 



COST OF PRODUCTION WITH CHINESE LABOUR 155 

the estate healthy for the Chinese or whatever labour is 
employed ? The Chinese, as a race, have keen business 
instincts. Where there is a choice, not even the most 
ignorant coolie will elect to go to an unhealthy estate in 
preference to a healthy one ; nor will the headman or 
contractor under whom he works, for the latter has to live 
on the unhealthy estate with his coolies. I have already 
mentioned that the Chinese have no natural immunity to 
malaria, although they do not die in numbers on the estates. 
They acquire in time a certain immunity ; but during that 
period there is much sickness, many days when they do not 
work, many journeys into towns for treatment among their 
friends and according to their own methods. All this has 
to be paid for, if the coolie is to live ; and he must be paid 
enough to live, for he is a necessity. It is, in fact, paid for 
by the higher wages he earns on the days he works. It 
may be taken as certain — even if the figures of the Estates 
Nos. 22, 27, and 28 do not prove it — that where an estate 
is healthy, Chinese can afford to, and do in fact, work at 
a cheaper rate than where the place is unhealthy. 

From the employer's point of view, whether the employer 
be European or Chinese, there are disadvantages from ill-health 
on an estate apart from the higher cost of production. It 
is a disadvantage to have a labour force constantly changing 
on account of ill-health. At times this leads to an actual 
shortage of even Chinese labour, which means a direct loss 
of crop ; for the rubber not taken any one day is lost for 
ever. It means, too, that a succession of tappers have to 
be trained, for tapping is skilled work ; and in the training 
some damage to the bark, the real capital of the estate, 
is unavoidable. Finally, where, as in this country, labour 
is imported at great expense, it is simple common sense 
to keep that labour at the highest possible state of efficiency. 
Only a healthy coolie, whether Tamil or Chinese, is efficient ; 
and the higher the efficiency the greater the production. So 
that, for Chinese no less than for Tamil labour, it would 
pay to control malaria, and money spent under medical 
charges would be well spent. I do not, of course, expect 
that the Chinese will patronise estate hospitals run on 
Western ideas; but I do think that money spent on subsoil 
drainage, oiling, removing coolie lines to healthy sites, and 



156 SE AFIELD ESTATE AND SUBSOIL DRAINAGE 

screened coolie lines, etc., to control malaria would improve 
the health and efficiency of the labour, and go far to make the 
Chinese dislike to hospitals a matter of indifference alike to 
the employer and employee — for there would be few sick. 

The Gross Cost of Disease. — A startling figure is revealed 
when we consider the gross saving to the estates employing 
Tamil labour in Group A. The gross crop was 12,528,782 
pounds; with the average saving of 7-78 cents a pound we got 
the sum of $974,737, or approximately ^114,000 sterling in one 
year — no mean return on the amount spent to improve health. 

If this be the saving to these few estates from which 
I have collected figures, what must be the total sum saved 
by all the estates in the Peninsula now able to employ 
Tamil labour forces because they are healthy ? It must 
run into many millions sterling, even on the estates only 
the careers of which have been traced in these pages ; and they 
are but a selection from the hundreds in the Peninsula. 

Finally, we shall see later on, there is some reason to 
believe that 100,000 lives have been saved in Malaya in the 
last twenty years by sanitation, and principally through the 
elimination of malaria. If we estimate the wealth of a country 
by what its inhabitants produce, the saving of these lives and 
the value of their work lead our thoughts into figures that 
stagger us ; but only do so, because we rarely count the cost of 
disease, and have not yet realised the value of medical research 
and the prevention of disease. As a nation, are we really 
practical ? 



CHAPTER XVI 

ON THE BORDER OF THE HILL LAND 

On the Coastal Plain and Mangrove belt we saw that malaria 
was controlled by drainage ; or by removing the labourers 
from the vicinity of jungle ; or, in some cases, by opening the 
jungle so as to push it away from the labourers' houses. On 
the hill land, the policy has been to concentrate the labourers 
at the centre of sanitary circles within which all mosquito 
breeding-places are destroyed. 

A number of estates border on the hills ; part of the land is 
flat, and part hilly. In controlling malaria on these, sometimes 
one method, sometimes another, and sometimes a combination 
of methods have been employed. In this chapter I propose 
to give some examples of the problem as it presented itself, 
and describe what was done in each case. 

North Hummock Estate. 

North Hummock Estate is situated on the border land about 
four miles north of the town of Klang. From the first it was 
intensely malarious, Europeans and Indians alike suffering. 
It consists of three divisions — as will be seen from the plan ; 
each was dealt with differently. 

Division A. — The lines on this division were situated on 
flat land at the end of a spur of the hill. A. timbrosus was 
abundant, and came from the unopened swampy jungle marked 
125 acres, part belonging to the estate, and part to a reserve 
of the Public Works Department of Government. 

In 191 1 permission was obtained from Government to open 
its portion (37 acres) of the land ; at the same time the estate, 
on my recommendation, opened the 125 acres which it owned. 
The result was an immediate improvement in health, as the 
following spleen rates show. 

157 



158 



ON THE BORDER OF THE HILL LAND 

Spleen Rates of Division A. 



Year. 


Number of 
Children Examiner]. 


Spleen Rates. 


1905. 

I gob .... 
igog December 
191 1 November 

1913 January . 

1914 February . 
19 1 4 November 
1916 November 
igi7 February 
igiS January . 
1918 June 
1920 January . 


5 
5 

32 
54 
32 
90 

87 

97 

74 

109 

103 
no 


40 
80 
59 
35 

9 

3 

4 

4 

1 

0-9 





The large increase in the child population and decrease 
in the spleen rate makes comment unnecessary. 



NORTH 

HUMMOCK 

ESTATE 




BUKIT 



RAJAH =| ESTATE 
Jungle Hi " 



Emery Walker l.ul. «. 



FlG. 45. — Plan of North Hummock. 
Areas subsoil drained marked black thus — 

Division B. — Here the malaria came from swampy jungle 
about twenty chains away. The problem was complicated ; for 



NORTH HUMMOCK ESTATE 



159 



that jungle belonged to another estate, and there was no 
intention of opening it. 

The problem was solved in a curious way. In connection 
with the water-supply of the adjoining estate, I had suggested 
a large catchment drain at the foot of the hill marked Bukit 
Rajah on the plan ; this was made, and other drains in the 
jungle were also dry. The result was to dry the jungle so 
that it no longer provided a breeding-place for A. umbrosus. 
At the same time some breeding-places of A. maadatus in 
the hill near to the lines were drained by subsoil drains. The 
spleen rate at once fell. 

Spleen Rates of Division B. 



Year. 


Number of 
Children Examined. 


Spleen Rates. 


191 1 November 

1913 January . 

1914 February . 
1914 November 
1916 February . 
1917. 

1918 January . 
1920 January . 




34 

72 

70 

122 

90 

112 

128 

I2S 


5° 

5 

2 

5 
3 

5 

6 

2 



In both 1917 and 1918 two of the children with enlarged 
spleens arrived ill, the result of malaria contracted in India. 
In 1920 two of the three children with enlarged spleen had 
recently suffered from malaria. They had been several years 
on the estate, where presumably they had contracted it. The 
third was a recent arrival from a malarious estate. 

Division C. — This division is of special interest. The 
lines were situated on a portion of the spur of hill land that 
terminates at the lines of Division A. The hills are intersected 
by a number of quite short ravines, each only about a couple 
of hundred yards long. They debouch on to the flat land 
where the soil was somewhat peaty. The ravines, except one, 
swarmed with A. maculatus, which were controlled by subsoil 
drainage of the ravine streams. As A. maculatus is never 
found in peaty water, it was unnecessary to pipe-drain a 
complete circle here, so the pipes ended as soon as they 
reached the peaty water. This knowledge of the habits of 
A. maculatus thus saved the estate much unnecessary expense ; 



160 



ON THE BORDER OF THE HILL LAND 



and the very small lengths of ravines to be drained made 
the cost of the control of malaria only a nominal sum — some 
$1500. 

The malaria had been so intense that even Banjarese, a 
race of Malayans, who are usually immune to malaria, could 
not live on the division, and the Tamils were decimated. The 
spleen rate shows the improvement. 

Spleen Rates of Division C. 



Year. 


Number uf 
Children Examined. 


Spleen Rates. 


1911 


12 


91 


1913 


H 


14 


1914 


77 


16 


1914 


55 


16 


1916 


42 


21 


1917 


44 


15 


1918 


72 


8 


1919 


62 


9 


1920 


55 


10 



In 1920 three of the six children with enlarged spleen gave 
history of fever previous to coming to the estate, and another 
new arrival had a greatly enlarged spleen. Here, as on other 
healthy estates, there are children who have imported their 
spleens and malaria. The true spleen rate, therefore, is 
under 4. 

For the whole estate the death rate of 1919 was 9 per 
mille. 

Subsoil drainage proved of advantage to the estate from 
a point of view other than health ; it has been of value in 
maintaining an efficient drainage system on the flat land. The 
attached letter from the manager gives an account of what the 
anti-malarial work has meant to the estate : — 

" North Hummock (Selangor) Rubber Co. Ltd., 
Klang, Zth November 1919. 

" Dear Dr Watson, — With reference to your request for 
an account of the work done on North Hummock Estate to 
improve the health, and particularly that done to control 
malaria, I have much pleasure in sending you these notes. 

" I joined this estate in 1910, and have been on it since that 
date, first as an assistant, and later as manager.* When I 
* The manager who carried out this excellent work was Mr R. K. Walker. 



NORTH HUMMOCK ESTATE 16 L 

first came, the estate was malarious, and all who lived in the 
bungalow on 'A' Division suffered severely from malaria. 
After the opening-up of the swampy jungle in that division, 
the malaria soon disappeared. 

" Division ' C,' in which the coolie lines are situated on 
small hills intersected by small ravines, was intensely malarious, 
so much so that a satisfactory labour force could not be got 
together there. The subsoil drainage soon improved the health, 
and this is now as healthy as any division on the estate. 
Indeed, there is at the present moment a larger labour force 
than is actually required. 

"On 'B' division subsoil drainage was also laid down in 
certain ravines adjacent to the lines, and along the foot of 
the hills. This was done not only to improve health, but 
because it was an effective way of preventing silt from reaching 
the open drainage system. VVe had first noticed this advantage 
on ' C ' division, and by its employment on 'B' division it 
was possible to prevent the 'CC' drain (the main drain of 
the estate) from becoming silted up. Many acres of rubber 
were thus saved from certain destruction, and some acres were 
reclaimed. The system of subsoil drainage has been systemati- 
cally extended throughout the estate ravines, quite apart from 
the health question, far beyond half a mile from any habitation 
and solely as an agricultural measure. 

" The cost of this subsoil drainage has been small. It has 
been carried out entirely by the estate staff without outside 
or engineering assistance. In very wet weather the ravines 
are kept under supervision, as occasionally small places scour, 
but many of the ravines have not cost a cent in repair, since 
the pipes were laid down in 1912 and 191 3. It has been this 
long and satisfactory experience of it which has made it the 
deliberate policy of the estate to deal with ravines by means 
of subsoil drainage. 

" The experience of the last few years has shown the 
advisability of deepening the drainage generally throughout 
the flat portion of the estate. This has been done, and led 
to an increased output of rubber. But it would not have been 
possible to maintain the increased depth in the drains, had 
the silt from the hills not been held back. To-day, in spite 
of a reduction in the amount of their normal food-supply, and 
in spite of difficulty of recruiting, the estate has become so 
popular with labour that there are now some 1600 men, women, 
and children on it. As the figures show, the health is excellent, 
and the death rate promises to be below 10 per mille for the 
year. 

" To sum up, by clearing and draining jungle, by deepening 



162 



ON THE BORDER OF THE HILL LAND 



the open drains in the flat land, by subsoil drainage of ravine 
streams, what was once an intensely malarious estate with an 
inadequate labour force is now one of the healthiest in the 
country, and possesses a large and contented labour force. 

" Finally, the measures taken to improve health have no 
less proved of the greatest value from an agricultural and 
financial point of view. — Yours sincerely, 

" T. Donaldson." 



Bukit Rajah Estate. 

I have known this estate as malarious since I came to Klang ; 
for, although it had been opened up for a year or two before 
my arrival, it was not a large estate, and coolies were living 
close to jungle. To-day it is a large estate, with some 4000 
acres opened, part of it hilly and part flat. The coolies are 
housed on different parts of the estate ; they are now almost 
free from malaria. The following gives a brief account of 
what was done to make them so. 

Triangle Lines. — These were close to the corner of a block 
of jungle marked 196 acres, through which runs the large 
drain "AA." In 191 1 this jungle was opened and planted on 
my recommendation : the spleen rates show the improvement. 



Year. 


Number Examined. 


Spleen Kates. 


1906 


7 


H 


1909 


22 


18 


1910 


42 


7 


1914 


54 


2 


1917 


102 


4 



Tamils at Sungei Binjai. — The fever in these lines came 
from the jungle of the 196 acres, and from what are now small 
native holdings on the south boundary. 

The spleen rates show the improvement. 



Year. 


Number Examined. 


Spleen Rates. 


1906 
1909 
1914 


8 

9 
48 


37 

22 

8 



BUKIT RAJAH ESTATE 163 

Of the four children with enlarged spleen in 1914, three 
came from a malarious estate. 

In 1917 the children were examined along with those 




in the triangle lines — the record of which has been given 
above. 

Banjarese. — At one time a number of these people lived 
along the edge of the jungle that is now Shelford Estate. 
They suffered greatly from malaria. 

They subsequently removed to native holdings on the road. 

N 



164 



ON THE BORDER OF THE HILL LAND 



Year. 


No. Kxamiiied. 


Parasite Bate. 


Spleen Rate. 


1904 


24 


62 


5° 


1905 


15 


60 


60 


1906 


15 




13 


1910 


35 




23 



Tamils at the Factory. — In 1904 the nearest jungle according 
to the estate plan was 40 chains away ; nevertheless the 
parasite and spleen rates were high. Later, they dropped to 
normal. In 191 7 the rise is owing to the recruiting of labour 
from an estate known to be intensely malarious. It is, however, 
easy to make the necessary correction ; and I give it as an 
example of the ease with which the correction can be made, 
and of how little one is liable to be misled by using spleen 
rates even on rubber estates where the population moves so 
freely. 



Year. 


No. Examined. 


Spleen Rate. 


Parasite Rate. 


1904 


42 


19 


41 


1905 


34 


32 


32 


1906 


7 


14 




1909 


72 


4 




1910 


5i 


6 


... 


1914 


11 







1917* 


11 


18 




igi7t 


19 


36! 





* Malayalams. 



t Tamils. 



; True rate = 0. 



Of the seven Tamils with enlarged spleen in 1917, all had 
come from a malarious estate ; and the same is true of the 
Malayalams. 

Blackwater Fever. — A case of this occurred in a bungalow 
in field 139 acres, before the jungle on the opposite side of 
the road belonging to North Hummock Estate was opened. 

Boon Hean Division. — In the previous places the problem 
was simply that of removing and draining jungle on flat land. 
The Division of which I now write was a pestilential spot, full 
of difficulties for the sanitarian. The coolie lines were scattered, 
and mostly close to jungle. Part of the land was hilly, and 
A. maculatus, the dangerous hill-stream mosquito, existed on it. 
Another difficulty was that 57 acres belonged to Government — 



BUKIT RAJAH ESTATE 165 

part being a quarry reserve which was of value for road upkeep, 
and which Government was strongly opposed to selling. The 
Government land was, however, intensely malarious. About 
1902 I chose the top of the hill as a site for coolie lines for 
the Public Works Department, going on the teaching that in 
a malarious country a hill ^as the best site, and that elevation, 
however slight, was preferable to the heavy clay of flat land. 
"As high ground as possible is the golden rule for a camp. 
Against the vertical uprising of malaria, elevation, however 
small, affords some protection." The lines were built on the site 
I selected, but the coolies promptly died of malaria ; and until the 
land was handed over to the estate they remained uninhabited 
and uninhabitable. On one occasion a man attempted to 
occupy the overseer's bungalow; but he, too, had to leave. 

To show how intensely malarious the whole area was in 
1909, I will give the spleen rates of the various lines. At B, 
14 out of 17 or 82 per cent, had enlarged spleen. At F, 
which is farther from the jungle, there were 9 out of 22 or 
40 per cent, with spleen. At C, the lines were within 20 yards 
of the jungle, and the spleen rate was 10 out of 11 or 90 
per cent.; while at C 2, which is 200 yards from the jungle, 
it was 8/15 or 53 per cent. In 1912 coolies were put into 
the lines D, E, and G, but the health was so bad they had to 
be moved. I have no figures of the spleen rates. 

In order to give the estate a healthy labour force, I decided 
it would be best to "scrap" almost all the existing lines and 
sites, and to create a new healthy site somewhere in the area. 
Accordingly, I made the following recommendations, which 
were adopted, with the happiest results: 

(1) Site A was selected as the future headquarters of the 

Division— but not because it was healthy ; for it was 
only a few yards from the Government reserve and 
site B where the spleen rate was 82. It was chosen 
because it was possible to abolish all breeding-places 
within half a mile. Site F would be protected by the 
same measures. 

(2) Sites C, C 2, D, E, and G were abandoned, because they 

were close to jungle. To make them healthy, it would 
have been necessary to open up extensive areas of 
jungle, and probably lay down considerable subsoil 



166 ON THE BORDER OF THE HILL LAND 

drainage; this was undesirable, since the jungle and 
hills formed the catchment area of the water-supply. 

(3) Part of the jungle marked 67 acres was drained and 
planted with rubber. The Government reserve was 
exchanged for a piece of land suitable for a rifle 
range. The reserve was cleared of jungle, and 
planted up ; while the ravines were drained by 
subsoil pipes. 

After these measures were carried out, the health improved, 
as the spleen rates show : — 



Year. 


No. Examiner]. 


Spleen Rates. 


l9og Lines at Site B 
igog Whole division 
1914 „ 
1915 
1917 


17 
65 
63 
49 
62 


83 
42 

14 

22 

6 



In 1917, there were four children with enlarged spleen; 
three of these belonged to one family which had recently come 
from a malarious estate ; the fourth child, with a spleen just 
palpable, came from an estate on which malaria had recently 
existed. There is now a large healthy labour force on a site 
which formerly was uninhabitable. 

Sungei Rasak Division. — This Division has always been 
healthy, for the lines have never been less than 30 chains from 
jungle, and I had advised the manager not to put new lines 
among the ravines ; they are situated at the end of a spur of 

the hills. 

Spleen Rates. 



Year. 


No. Examined. 


Spleen Rates. 


1910 

1914 
1915 
1917 


12 
74 
34 
46 


15 
14 

8 
4 



In 1917, one of the two children with enlarged spleen had 
been on the estate only a week, showing it had brought the 
enlarged spleen to the estate. 

Death Rate of Estate. — The various measures taken to im- 



BUKIT RAJAH ESTATE 



167 



prove health, chiefly the anti-malarial work, have resulted in a 
lowering of the death rate. The labour forces and death rates are 
taken from the official report of the Labour Department, except 
for 1919, which are based on the average monthly population. 



Year. 


Labour Force. 


Death Rate per mille. 


1906 


95o 


43 


1907 


1150 


45 


1908 


II25 


63 


1909 


993 


29 


1910 


1 144 


33 


1911 


»43 


39 


1912 


1 146 


34 


1913 


1254 


39 


1914 


1 146 


14 


1915 


"57 


19 


1916 


1215 


7 


1917 


1269 


14 


1918 


1374 


32* 


1919 


1459 


10 



* Influenza. 

Further comment is hardly necessary. 

Batu Blah Drainage. — Close to the Boon Hean Division of 
Bukit Rajah Estate are many kampongs or native holdings. 
Until 1916, the drainage of the kampongs around Batu Blah 
Hill was defective. A. umbrosus was to be found in many 
drains and in wells around the hill. Consequently, malaria was 
prevalent. Two European houses and several of the better 
classes of native houses, built here from the spread of the town, 
were abandoned on account of their unhealthiness. 

In 1914, I represented this to Government; in 1916, about 
$3000 were spent on an open drainage system. The spleen 
rate of Batu Blah Malay School has steadily fallen since. In 
1919, two of the three children with enlarged spleens were old 
residents ; the third lived \\ miles away. 

Batu Blah School. 



Year. 


No. Examined. 


Spleen Rates. 


1909 


53 


45 


1914 


60 


45 


1916 


62 


3° 


1917 


67 


37 


1918 


54 


20 


1919 


53 


5 



168 ON THE BORDER OF THE HILL LAND 

The abandoned houses have been reoccupied. There is 
now no complaint from the natives ; at first they said they 
could not get sufficient water ; their wells were dried up or 
closed, and they had to go some distance to the pipe supply. 
Now they are reconciled, as the improved drainage has given 
them larger crops — mainly of rubber. 

Midlands Estate. 

When first opened in 1906 this estate was intensely 
malarious, because the first clearings were on the hills, and 
the labour force was housed on ravines teeming with A. 
maculatus. 

Quinine was given, and the coolies were fed in the morning 
before going to work, with a certain improvement in health, 
but not sufficient to enable a healthy Indian labour force to be 
established. 

When more of the estate had been opened, sites on the flat 
land were available, and the hill land sites were abandoned. 
The estate is now worked in two divisions. The North 
Division coolie lines were moved 25 chains or \ mile, and 
the South Division lines 50 chains. In neither case was it 
possible to move the lines h mile from all hills, so additional 
measures were taken to control the breeding-places of A. 
maculatus within the sanitary circle, namely subsoil drainage 
and oiling. 

There were difficulties with the subsoil drainage in certain 
places owing to the impervious clay soil, and much of this 
drainage was pulled up. It is used now as subsidiary to oiling 
in short lengths round the hills. Open drains round the hills 
are also oiled for 1 chain from the foot of the hills ; special 
attention is paid to seepage areas. It has not been found 
necessary to oil the drains in the flat bottom of the valleys, 
partly because the main drain contains peaty water, which 
never contains A. maculatus, and partly because the oiling of 
the hill-foot drains pollutes the other drains on the flat. 

South or Old Division. — The removal of the lines was 
commenced in July 1913 and was completed by February 
1914. 

The effect of this and the other measures is shown in the 
fall of the spleen rate. 



MIDLANDS ESTATE 



169 



Year. 


Number of 
Children Examined. 


Spleen Rates. 


1906 

1907 

1909-IO 

I914 

1917 

1918 

1920 


61 

43 

153 

78 

48 

"5 

H3 


65 
83 
45 
21 

6 
2 
2 



In 1920 there were three children with enlarged spleens ; 
two of those were a brother and sister locally recruited three 
months before ; the other was a child many years on the 
estate, whose spleen was just palpable. The true spleen rate 
is, therefore, under 1 per cent, and is in keeping with the low 
death rate. 

In December 1914 in a report I made this remark: — 

"But marked as this improvement is, an analysis of the 
figures gives curious and interesting independent evidence of 
the improvement which is taking place. In 1909-10, in the 
lines situated on the Government Road, and subsequently 
abandoned, 21 out of the 22 children had enlarged spleen; 
the spleen rate of the children who had been over six months 
on the estate was 81 ; and out of the total 153 children on this 
division there were only 4 infants. 

" Now I find that among the 57 children who have been 
longest on the new site (since July 191 3) only 8 or 14 per 
cent, have enlarged spleen, not a single one (except 1 in 
hospital) is ill, and there are 9 fat, healthy infants. On the 
other hand, of 21 children removed to the new site in February 
1914 still 9 or 42 per cent, have enlarged spleen ; but even here 
only 1 is ill, and there are 3 healthy infants." 

This note is interesting, as giving a glimpse of spleen rates 
during a transition stage from high to low. 

North Division. — The same policy was advised for the 
North Division of the estate. On 3rd August 1910 I wrote 
to the manager : — 

" Sites in proximity to the hills which pretty much follow 
the cart road, as shown on the plan, are to be regarded as 
unhealthy. It is, therefore, desirable to put the lines and 
bungalow as far as possible from them. I, therefore, advise 
that the new buildings be put close to the pipe line. This will 
put them close to jungle, which is also unhealthy, but it might 



170 



ON THE BORDER OF THE HILL LAND 



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MIDLANDS ESTATE 



171 



be possible to make the clearings in the near future along the 
pipe line, thereby improving the health of the new buildings." 

The buildings were put on the road close to the hills, and 
proved unhealthy. Between January and October 1914 some 



Per 

Cent. 


Jan. 

Feb. 

Mar. 

Apr. 

May 

June 

*July 

Aug. 

Sept. 

Oct. 

Nou. 

Dec. 


40 
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FlG. 48. — Chart of percentage of Admissions for Malaria, Midlands Estate. 

ravines were pipe-drained and others oiled, which improved 
the health. In 1915, 1917, and 1918 various blocks of the 
flat land beyond the pipe line were opened up, pushing the 
jungle some 40 chains from the pipe line, and making it 



172 



ON THE BORDER OF THE HILL LAND 



possible to remove the labour force to the site suggested in 
1910; and the whole labour force was removed early in 1918, 
with satisfactory results, as the figures will show. Not until 
1919 was the jungle taken a full half-mile from the lines. 

The plan, showing the abandoned sites, gives a better idea 
of the policy adopted than anything I can write ; so I refer 
the reader to the study of it. 

The drainage and oiling were not in force until towards the 
end of 1914, and so at that date the spleen rate was still high. 
The labour force was not removed from the hills until March 
and April of 1918. 

Hence the spleen rate of this division fell at a later period 
than on the South Division. 



Year. 


Number of 
Children Examined. 


Spleen Rates. 


1909-10 
1914 

1918 
1920 


21 

22 
20 
29 


76 

63 
20 

6 



In 1920 there were two children with enlarged spleen ; one, 
born on the estate, had a spleen barely palpable ; the other, a 
local recruit, had been about three months on the estate. 

Death Rates. — With the falling spleen rates the death rates 
came down as the following table shows. In the years 1909 and 
1910 large numbers of Telegu coolies were recruited. It was 
not until the end of 191 1, when Mr Harrison became manager, 
that special measures against A. maculatus were commenced. 



Year. 


Average Population. 


Death Bate. 


1907 


75o 


73 


1908 


1256 


165 


1909 


1369 


56 


1910 


1114 


no 


1911 


940 


189 


1912 


861 


82 


1913 


824 


78 


1914 


713 


42 


1915 


528 


15 


1916 


547 


14 


1917 


597 


II 


1918 


622 


48* 


1919 


616 


8 



Influenza. 



DAMANSARA ESTATE 



173 



In the first four months of 1920 only one death has 
occurred ; it was from epilepsy. 

The approximate cost of oiling each area of a half-mile 
radius is $400 per month.* 

This estate is a brilliant example of how intense malaria 
can be overcome by removal of buildings to the best sites, 
coupled with subsoil drainage and oiling to breeding-places 
within the new sanitary area. Quinine is not given to any 
except the sick. 

This work has been carried out entirely by the manager, 
Mr C. R. Harrison, and reflects the highest credit on him. 



Damansara Estate. 

This estate is situated on the border of the hill and flat 
land. The measures taken to improve health have been 
giving quinine, opening swampy jungle, removal of labour 
from hill to flat land, and oiling. The original Damansara 

Parasite Rate. 



Year. 


Number of 
Children Examined. 


Parasite Bate. 


1904 


9 


22 


Spleen Rates. 


Year. 


Number of 
Children Examined. 


Spleen Rates. 


1904 
igog 
1911 

1913 
1914 
1915 
1920 


9 

9 

10 

13 
15 

20 

33 


II 

22 
30 
23 
13 

5 
3 



Estate acquired Telok Batu Estate in 1906, and Labuan 
Padang Estate in 1907. From a medical point of view, I 
regard the group of estates as composed of five divisions ; as 
the coolie lines are situated in five groups at some distance 
apart and under different malarial influences. 

* Owing to the great increase in the cost of oil, additional areas have 
been subsoil drained. 



174 



ON THE BORDER OF THE HILL LAND 



Some spleen and parasites rates for 1905 and 1906 have 
been omitted, as the records of Divisions " A " and " B " had 
unfortunately not been kept separate. 

Division "A " is situated on the river. To improve the 
health quinine was given with the greatest care by Mr H. F. 
Browell from 1904. In 1910 about six acres of secondary 
jungle and undergrowth was removed. In 1912 and 1913 
150 acres of land belonging to another estate on the opposite 
side of the river was opened. Some jungle still remains within 
40 chains. 

The figures on the previous page show the result. 

Division "B." — On my recommendation, in 1910, jungle to 
the extent of 108 acres of flat land was opened. Later on, 
still more flat jungle belonging to an adjoining estate was 
opened, and hill-land ravines extensively oiled. 

Parasite Rate. 



Year. 


Number of 
Children Examined. 


Parasite Rate. 


1904 


32 


40 


Spleen Rates. 


Year. 


Number of 
Children Examined. 


Spleen Rates. 


1904 
1909 
1911 

1913 
1914 

1915 
1920 


32 
31 
27 
22 

39 

55 
39 


15 
51 
H 
27 
20 
12 




Division " C." — The lines were situated on a low spur of 
the hills, with streams breeding A. maculatus on each side. 
In 1910 I recommended that the lines be removed to a site 
on the flat, then under swampy jungle. Part of this jungle 
belonged to another owner, but it was acquired by the estate, 
and the whole block comprising 87 acres was drained and 
planted. Division "C" was removed to it, and on it was 
built the estate hospital. 



DAMANSARA ESTATE 

Spleen Rates. 



175 



Year. 


Number of 
Children Examined. 


Spleen Rates. 


1909 
I9II 

1913 

1914 
1915 
1920 


9 
1 

9 

22 
18 
27 


IOO 
IOO* 

22 

27 
16 

7 



' Lines removed to new site in 1911. 

In 1920, one of the two children with enlarged spleen was 
a local recruit from an unhealthy locality. The true spleen 
rate was 3-5 per cent. 

Division " D." — Formerly an intensely malarious spot. Two 
streams breeding A. macitlatus were on the sides ; in front was 
a mass of swampy, flat-land jungle. This is the estate to 
which I refer in Chapter XI. on the effects of malaria in 
children : — 

" Among the children malaria is no less severe. On one 
occasion I was asked by a manager to advise him what should 
be done for the children, as fifteen had died in the previous 
two months out of a total of thirty-three. He told me a 
native clerk was giving them quinine daily. I examined the 
blood of the remaining eighteen, and easily found parasites in 
seventeen. The manager then gave personal attention to the 
quinine administration of the children, and there were only two 
deaths in the next three months, these being children who were 
seriously ill before he took it in hand. The effect of this 
terrible death rate on the coolies was such, that even although 
they were living in good lines built less than three months 
before, and on land opened for ten years, they declared the lines 
were haunted. The lines had to be pulled down and rebuilt 
elsewhere." 

The new site was on the river about 300 yards from the 
old one. The health improved when the flat land across the 
river was planted, and a ravine, part of which is probably not 
so suitable as it was for A. macnlatus, on account of shade, 
was oiled for a time. (See Chapter XXV. on the Mosquitoes 
of Ravines.) 



176 



ON THE BORDER OF THE HILL LAND 

Parasite Rates. 



Year. 


Number of 
Children Examined. 


Parasite Kates. 


1904 
I905 
1906 


12 
17 
18 


IOO 

II* 
94 


Spleen Rates. 


Year. 


Number of 
Children Examined. 


Spleen Rates. 


1904 
1909 
1909 
1911 
1913 
1914 

1915 
1920 


12 
12 
30 
24 
39 
44 
33 
44 


? 5 
100 old site 

76 new site 

66 

76 

5o 

66 

9 



* Quinine given carefully. 

Division " E." — The lines are situated on the end of a spur 
of the hills, on one side of which is a ravine, while in front is 
flat land. The most important ravine has been oiled inter- 
mittently since 1914, and regularly since 1918. The ravines 
farther off are under the shade of heavy rubber and small 
undergrowth, and so are less suitable for A. maculatus than 
they were previously. 

Spleen Rates. 



Year. 


Number of 
Children Examined. 


Spleen Kates. 


1906 
1909 
1911 

1913 
1914 

1915 
1920 


26 

13 
6 
11 
12 
19 
33 


76 
IOO 

66 
81 
83 
84 

6* 



1 True rate. 3. 



In 1905, when quinine was being given with great care, 
the parasite rate of seventeen children was 23-5 per cent. 

In 1906, parasites were found in twenty-five out of twenty- 



DAMANSARA ESTATE 



177 



six children ; the single child without parasites had suffered 
from " fever " four days before, and was on quinine ; its spleen 
was enlarged. 

In 1920, of the two children with enlarged spleen, one was 





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100 


10 

































































FlG. 49.— Chart of Death Rates of Damansara Estate. 



a local recruit only six weeks on the estate ; the other child 
was born on the estate. All the children looked well. 

The Death Rates. — With spleen rates so high, one would 
expect to find high death rates, if many new coolies were 
employed ; and this was so. The estate originally was not 
uniformly malarious, as will have been noticed from the spleen 



178 ON THE BORDER OF THE HILL LAND 

rates ; but the two Divisions last mentioned had at one time 
an appalling mortality not only among the children but among 
the adults. For example, in 1906, on Division " E" there were 
116 coolies on the 1st January; 170 were recruited from 
India. Of the 286, 26 deserted, and 60 died ; the death rate, 
worked out on the quarterly labour force, was 300 per mille. 

In 1907 the death rate of the 275 coolies on "E" Division 
was 178 per mille; of 275 coolies on "D" Division it was 
200 ; and of 700 on Divisions " A " and " B " it was 138. These 
are examples of what malaria can do ; and they occurred 
despite the most careful administration of quinine. On 
Division " E " the names of the occupants of each room were 
put on a special check roll, and each person was accounted for 
and given quinine daily, with extra doses of quinine solution 
when ill. Euquinine was given to the children. 

The European staff suffered no less than the Asiatic, and 
the manager had to be invalided in 1907. Yet this intense 
malaria has been slowly overcome, and health has steadily 
improved since 1910, when radical methods were adopted on 
Divisions " A " and " B," namely, the opening of swampy jungle 
and removal of coolie lines. Later, oiling, more or less 
efficiently carried out on the other Divisions, the opening of 
some jungle, and probably the heavy and close shade of rubber 
trees and ferns now growing in some of the ravines, have 
contributed to reduce the number of stream-breeding mosquitoes. 

The death rates show the nature of the change : — 



Year. 


Labour Force. 


Death Rate per mille. 


1906 


800 


146 


1907 


1155 


157 


1908 


1005 


176 


1909 


772 


III 


1910 


926 


152 


1911 


892 


116 


1912 


887 


49 


1913 


1186 


52 


1914 


1251 


63 


1915 


1295 


29 


1916 


877 


41 


1917 


800 


35 


1918 


703 


123* 


1919 


795 


17 



* Influenza. 

Still further improvement may be anticipated with confidence. 



JUGRA HILL 179 

Jugra Hill. 

The estates in the district of Kuala Langat, whose history 
is given in Chapter VIII., are on flat land, and the malaria 
from which they suffered at one time was carried by A. umbrosus. 
But in the district rises Jugra Hill, a mass of granite 915 feet 
high, isolated from all other hills by some 15 to 20 miles of 
flat land. It is not uninteresting, as Dr Leicester 7 remarks, 
that the mosquitoes of the hill are not those of the surrounding 
flat land, but of hill land. And among the hill mosquitoes is 
A. maculatus, the stream breeder. As a result of its presence, 
all around Jugra Hill has been extremely malarious, while 
only a short distance from it people have enjoyed good health. 

What amounts to an experiment took place a few years 
ago, when a set of lines belonging to the Public Works Depart- 
ment was removed from the base of the hill to a spot a mile 
from it. The result was an immediate and marked improvement 
in the health of the coolies, which has ever since been 
maintained. The condition of the coolies in 1901 and 1902 
can be seen from the following extract from a report dated 
15th January 1902, made by me to the Government on the 
prevalence of malaria in Jugra. 

" Para. (4) . . . But I would like to draw attention to some 
observations made at the P.W.D. coolie lines at Permatim 
Pasir which show that the malaria is not confined merely to 
the town, but extends round the foot of the hill, and which 
also explains the absolute refusal of many of the coolies to 
remain after the term of their agreement had expired, although 
they were willing to work at Klang. 

"(5) On 5th February 1901, out of nine persons in the 
lines one alone was healthy. 

Two men and one child had malarial fever. 
Two children, two men and one woman had enlarged 
spleens, the result of repeated attacks of malaria. 

I was informed about fifteen coolies were living there at the time. 
"(6) On 10th July 1901, I found of these P.W.D. coolies: — 

In the lines : 

Two women, one man and three children with malarial 
fever. 

O 



180 ON THE BORDER OF THE HILL LAND 

In the hospital : 

Seven with fever, and three with enlarged spleens and ulcers. 

At this time there were about thirty-four persons living in the 
lines. 

" (7) On 7th January 1902, there were eleven children under 
ten years present at my visit. All without exception had 
enlarged spleen. Two women had fever. 

" The overseer volunteered the statement that fifteen children 
had died within the past six months, which is not improbable, 
as malaria often affects children severely." 

As the result of these representations the lines were removed 
in 1903 from the immediate foot of the hill, and, taking no 
risk, I advised they should be put a mile from the hill. 

The result has been successful in the highest degree. From 
1903 onwards I have often gone to the lines, and I have never 
once found a coolie in them suffering from fever, although 
doubtless a coolie may occasionally do so. 

On 18th January 1910, I examined fourteen children in the 
lines. Two of them had splenic enlargement, and the overseer 
told me both had come to the place about a year before from 
other P.W.D. lines, and that they had not suffered from malaria 
since their arrival. 

The overseer said he had been two years in the lines, 
and had not suffered from fever. No children had died since 
he had been in charge ; the only death had been that of a 
coolie who was ill when he arrived from India, and had died 
shortly after his arrival. No adult or child had fever on the 
day of my examination. 

That no improvement has taken place in the health condition 
at the foot of the hill, is to be seen from an examination of 
thirty-five Malay children in the Permatim Pasir School made 
on 16th May 1909. Of the thirty-five, eleven, or 35 per cent, 
had enlargement of the spleen. This is in marked contrast to 
the P.W.D. coolies only a mile from the hill, and from the 
freedom from malaria on the Estates " KK " and " LL," distant 
1 \ and 2 miles respectively. 

The town of Jugra, situated at the foot of the hill, is the 
official headquarters of the district ; but it has been so 
persistently malarious since 1896 that in 1917 the Government 
decided to remove it to a site on flat land about 5 or 6 miles 




[To face page ISO. 



KARIMON ISLAND 181 

from the hill. The new buildings are now in course of erection. 
The new site is close to Estate " TT," so it should be healthy. 

Practically half of the shop houses of the town have been 
abandoned or pulled down : more than half of one side of the 
street has disappeared. The place forms a picture of desolation 
to which the camera fails entirely to do justice. 

In passing, I may mention that the story of the malaria of 
Jugra given in Volume I. of the Studies from the Institute for 
Medical Researcli is entirely wrong. The coolies came to Jugra 
to work the quarries in 1898, not in 1896 as stated ; and malaria 
had been rapidly increasing for two years before their arrival, 
as the table printed in the Study shows. The coolies did not 
introduce the disease ; they were its victims. 

Karimon Island. 

I will now give an instance where the hill land bordered, not 
on flat land, but on the sea. 

At Malarco, on the Great Karimon, one of the Dutch 
islands of the Archipelago, some 30 miles from Singapore, 
a company had started a large factory for the treatment of 
jelutong, a "wild rubber" found in the Malay Archipelago and 
Peninsula. A first-class factory, with electricity as its motive 
power, had been erected. A model village had been built, 
and a pure water supply had been brought in from a reservoir 
3 miles away. The village was on a reclamation, with deep 
water immediately beyond ; and the latrines were over the sea. 
Everything that could be thought of to improve health had 
been done, including the clearing of jungle and undergrowth 
for some acres round the site. Despite everything, the 
people were " much troubled with a virulent form of malaria." 
Mr Galbraith, the General Manager in the East, invited 
me to visit the island, and advise on what should be done to 
improve health. 

This I did on 22nd July 1912. The factory and village 
were on the end of the island which rises steeply from the 
sea, as is seen from the photograph. In front of this is a 
small island, which thus forms a breakwater to Malarco. 
Through the Strait a steady breeze blew both night and 
day during my visit. For the general sanitary conditions, I 
had nothing but praise. " The buildings in which the coolies 



182 ON THE BORDER OF THE HILL LAND 

are housed are of excellent design, of good construction, 
maintained in good order, and well laid out," was my note 
on the housing ; and other sanitary arrangements were equally 
well carried out. 

There was a coolie population of between 800 and 900. 

Evidence of Malaria. — There being practically no native 
child population, no spleen rate could be obtained. The death 
rate was also valueless. When ill, many of the Chinese left 
for Singapore, where indeed a number died in the hospitals ; 
eight are reported to have died in Singapore hospital in 
January 1912; but many Chinese refuse European treatment, 
go to friends, and die unknown to the manager of the place 
they come from. The hospital statistics showed that in 191 1 
there had been 811 admissions, of which 72 per cent, were 
for malaria; from 1st January to 20th July 1912, there had 
been 389 admissions, malaria being 61 per cent, of them. 

The Europeans were suffering no less than the Asiatics, 
and a number had resigned. Of a total of thirteen former 
residents, I was informed that eleven had suffered from malaria. 
At the time of my visit, fourteen of the twenty-two had had 
malaria ; some of the others had been only a short time on 
the island. 

There had been five cases of blackwater fever, three of 
which had been fatal. 

The cause of the malaria was A. maculattis, which I found 
breeding in large numbers in every stream and spring on the 
hillside except two. The more the hillside was cleared of 
vegetation to stop the malaria, the more extensive became 
the mosquitoes' breeding area ; and the measures taken to 
reduce malaria were really causing its increase. Accordingly, 
among my recommendations, I said : " With regard to the 
clearing of the jungle, I do not recommend this area be 
extended. Rather I would advise that all mosquito breeding- 
places in the already cleared area be abolished." 

I also advised that the best way " to eradicate these 
mosquitoes is to put all the water on the hillside underground." 
The hillside was a mass of granite boulders, some of large size, 
and others small ; and most of it was very steep. " In the 
steepest portions of the streams, I noticed the water was 
already finding its way underground among the boulders, 
and that the water only appeared where the grade was less 




Fig. 51. — Malarco. 
Great Karimon Island. 




Fig. 54.— At Malarco. 
The Line of a Buried Stream. 



[7"o face page 182. 



KARIMON ISLAND 183 

steep." Therefore I advised that this natural subsoil drainage 
be assisted ; subsoil pipes being laid down where the water 
could not be drained in the natural channels. As a warning : 
" In work of this kind, where everything tiny, spring or trickle 
of water oozing from the hillside is a danger, the first essential 
is thoroughness. It is also important to remember that new 
springs may appear in wet weather, if the whole be done in 
a dry period." 

The same energy and thoroughness with which Mr 
Galbraith had developed the factory, and created a model 
village, was brought to the anti-mosquito work. Writing on 
19th December 191 2, Mr Galbraith said : — 

" I had hoped to advise you before Christmas that we had 
sunk all the streams, but the weather has been so wet that we 
have been forced to suspend work until January. There are 
nineteen streams' altogether to sink, besides a lot of little 
streamlets coming out of the foot of the hills along the 
seashore, and a dozen small outlets in the cutting behind the 
factory. We have cleared and exposed all the streams from 
end to end where they run on the surface, and have, so far, 
buried twelve, leaving seven large streams to finish. We have 
also done most of the work in the cuttings and cleared the 
seashore springs, and towards the end of January I hope to 
advise you we have finished. ■ 

" The buried streams are holding fairly well notwithstanding 
the heavy rains (twice as much has fallen as in Singapore), and 
so far I don't think we have had to repair 500 feet out of about 
11,000 buried." 

On 31st December he added : — 

" I may say that at first some of our pipes were displaced, 
but this was partly due to insufficient depth and the incidence 
of heavy rain immediately after placing them, and they were 
almost perpendicular. We have since used a light mixture of 
sand and cement to cap all streams whether in pipes or only 
under rocks (as per sketch on next page), and any recent trouble 
we have had is due to silt blocking the stream and the water 
then bursting out; but this in turn was due to the storm water 
finding an entry higher up, and in time we expect to get over 
such accidents entirely. 

" I cannot say the improving health is yet due to the burying 
of streams — indeed, I do not think it is to any great extent — 
the number still open in our more or less restricted area is too 
large to stop breeding yet awhile. By March, however, I hope 



184 



ON THE BORDER OF THE HILL LAND 



to show you the hills as dry as bones two days after the 
heaviest rain." 

On 15th March 191 3 I visited the island, and found the 
hills as dry as had been predicted, and the health greatly 
improved. Doubtless the heavy rains had helped to scour out 
the anopheles, for they breed most freely in dry weather. 

The work had been done splendidly ; the photos show how 
steep the hillside is, and the difficulties that must have been 
overcome to make the drainage an engineering and anti- 
mosquito success. The experiment was promising. While 
there had been difficulties, owing to the steepness of the 



Lalanq 
-j;- '>'; >E arth -J pounded- : down «{# j- 




Cement 







FlG. 53. — Subsoil Channel at 
Malarco. 

FlG. 52. — Malarco — Subsoil Drain. The 
Storm Course is divided wherever 
possible. 

hillside, and the complete unfamiliarity with anti-malaria 
work of those who were responsible for its execution, all the 
difficulties had been successfully overcome by the splendid 
energies and intelligent appreciation of the essentials brought 
to the work by Mr Galbraith, Mr Grant, Mr Day, and others 
of the staff; and all A. maculatus breeding-places had been 
destroyed. There was in its favour that no danger came 
from the seaside of the settlement; the jungle-clad hinterland 
beyond the clearing was steep hill land and probably harmless 
— for no A. umbrosus was taken at my visits. In other words, 
no dangerous anopheles now existed ; or, if present, were so 
only in small numbers. 

So I was hopeful of a great improvement in health by the. 



KARIMON ISLAND 



185 



end of 191 3. But on my return to the East I found that the 
heavy fall in the price of rubber had practically closed down 
this jelutong factory, and only some 200 coolies were left. 
Soon afterwards I heard the factory had been sold, and the 
place abandoned. Caution must therefore be exercised in 
accepting an incomplete record ; it never was to be completed. 
Yet for what they are worth, I give the total admissions and 
total out patients ; they eliminate errors of diagnosis, and any 
anti-malaria success should lead to a reduction of sickness from 
all causes. They are the last figures I received. 



Month. 


Labour Force. 


Admissions. 


Out Patients. 


1911. 


1912. 


1911. 


1912. 


1911. 


1912. 


July 

August . 
September 
October . 
November 
December 


580 
530 
600 
760 
850 
690 


960 
860 
800 
890 
920 
860 


27 
34 
73 
117 
102 
85 


64 
68 

41 

33 
34 
22 


1761 
1647 
2348 
1540 


693 

535 
412 
316 
230 
152 



For January and February 1912 and 191 3 the figures were : — 



Month. 


Labour Force. 


Admissions. 


Out Patients. 


1912. 


1913. 


1912. 


1913. 


1912. 


1913. 


January . 
February 


750 800 
S08 840 


76 

44 


37 

36 


1158 
751 


249 
183 



On the day of my visit in 1913 there was only one case of 
malaria in the hospital out of the whole labour force. 

I think the story worth telling, both for the sake of the 
splendid fight against malaria, and for the guidance it may be 
to others in similar circumstances. On my last visit one 
member of the staff, in commenting on the difference in 
health between the time of speaking and a year before, said : 
" If ever again I have to do a job in a place like this, I will 
begin by killing the mosquitoes. The rest of the work will 
then be quite simple." 



CHAPTER XVII 

OILING 

In 1901 oiling was employed at Port Swettenham for a few 
months during the height of the epidemic, and until the new 
drainage system became effective ; then its use was dis- 
continued. On the flat-land estates of the Coastal Plain, 
malaria was so easily controlled by good drainage that oiling 
was unnecessary ; indeed it would have been impossible to 
oil the unopened jungle swamps. 

The grave problem of persistent malaria in the hill land 
again raised the question of oiling ; but in rapidly running 
water the prospect of success seemed remote indeed. 

" Drainage and eradication of breeding areas is the all- 
important work in the anti - malaria campaign " was the 
conclusion reached in Panama ; and it confirmed my own 
views. 

During a visit to Panama in 1913, I 22 studied carefully 
the habits of the anopheles, and the methods of mosquito 
control. Excellent results were obtained from a mixture of 
crude mineral oil and a larvacide (the latter a poison made 
from resin, carbolic acid, and caustic soda), which was used both 
in pools and streams. The American species of anopheles are, 
however, different from those of Asia ; no Panama species lives 
in fast-running water like A. maculatus or A. aconitus. It was, 
therefore, impossible to be sure that the oiling, which gave 
good results in Panama would be equally effective in the hill 
streams of Malaya. Nevertheless, I decided to put aside all 
preconceived ideas, and investigate the subject de novo. If 
mixtures of mineral oil alone were found, after a careful and 
thorough trial, to be useless in controlling A. maculatus in our 
ravines, then it seemed me worth going to the expense of 
manufacturing the larvacide and giving it a trial. 

If success was to be obtained, the oil must be got to spread 



SUCCESS WITH OILING 187 

rapidly after spraying, and it must be applied not by drip 
barrels, but from sprayers which could be carried in the ravines, 
and from which the oil could be applied to each tiny seepage, 
spring, and side pool in the ravine, as well as along the edges 
of the main streams. Ordinary kerosine was too thin ; the 
liquid fuel usually supplied too thick ; but by trial, a mixture 
was obtained that appeared to have the necessary qualities. 
It now remained to try it on a ravine stream containing A. 
maculatus. 

On Sungei Way Estate there is a ravine which I had 
known to contain A. maculatus for many years. It was 
examined, found to contain the larvae in large quantity, and 
then oiled thoroughly. A week later it was free from larvae ; 
indeed there was a complete absence of all aquatic insect life, 
even Chironomus was dead or absent. On the surface of some 
of the side pools large numbers of adult insects were found 
dead ; wherever touched by the oil, green vegetation was dead 
and brown in colour. Mr W. S. Reeve-Tucker, the manager, 
carried out the oiling with great thoroughness ; and on 25th 
August 1914 I wrote to him : — 

" It will be of interest to your Directors to learn that by 
oiling with the mixture in use on Sungei Way, one of the 
ravines in the West Division has been kept free from Anopheles 
for several months. Formerly they bred freely in it. I am 
encouraged to think that this is not merely due to the physical 
difficulty the larvae would have of getting air when oil is on the 
water, but that some change has actually taken place in the 
water as a consequence of the oil, and a change which would 
make it uncongenial to the stream-breeding mosquito. My 
reason for thinking this is that in the bottom of the ravine 
a green slime has developed, in the presence of which I have 
never found dangerous anophelines. It is common enough in 
flat land. 

"The practical point is that it is, in my opinion, additional 
proof of the value of oiling. And if your Directors decide 
to oil the ravines, instead of pipe-draining them, they can be 
satisfied that it will kill out the harmful mosquitoes." 

The mixture had been more effective than we had antici- 
pated ; no larvacide or other poison had been mixed with the 
oil ; we had got an alternative to subsoil drainage. 

Mr Reeve-Tucker was now satisfied of the value of oiling ; 
and placed it under the immediate care of Mr Muir, engineer 



188 



OILING 



of the estate, of whose work I cannot speak in too high praise. 
The result of the oiling was a rapid improvement in the health 
both of Indians and Europeans. 

Death Rates. 



Year. 


Indian 
Labour Force. 


Death Rate. 


Year. 


Indian 
Labour Force. 


Death Rate. 


1906 
1907 
1908 
1909 
1910 
1911 
1912 


400 

375 
282 
260 
232 
270 
320 


15° 
56 

223 
6l 

35 

121 

106 


1913 
1914 

1915 

1916 
1917 
1918 
1919 


349 

381 

342 

333 

3°5 
310 
294 


63 
36 
32 
20 
29 
48 
26 



The oiling on an adjacent estate within the half-mile radius 
of the Sungei Way lines, has not, until recently, been as 
efficiently carried out as I desired ; otherwise I believe the 
results would have been better than they are. Yet the health 
is better than the figures indicate ; for not infrequently coolies, 
who have absconded to unhealthy estates, have returned to 
Sungei Way to die practically without doing a day's work; 
for example, in 1919, no fewer than three of the eight deaths 
were among these " returned bolters." 

The manager and his wife have had one attack of malaria 
since 1913 ; it was contracted at Morib. His child, aged six 
and a half years, has not had malaria. 

Formerly Mr Muir, his wife, and his two elder children 
were frequently attacked ; one of the children was seriously ill. 
During the past four years Mr Muir has had one attack of 
malaria ; his wife and three children have been completely free 
from it. An assistant has been on the estate over three years, 
another over two years, without being attacked. 

Spleen Rates. — These show the improvement that might 
be expected. In 1906 all the children, thirteen in number, had 
enlarged spleen ; and in 1909, all of four. In 1916 it was 
fourteeen out of thirty-six (38 per cent.) ; and in 1920 it was 
seventeen out of sixty, or 28 per cent. An analysis of the 1920 
figures is, moreover, of interest. The children are divided 
into those born on the estate ; those from India — small and 
large ; and local recruits. 



HOW OIL ACTS 



189 





Number of 
Children. 


Number with 
Enlarged Spleen. 


Spleen Rates. 


Born on Estate .... 
Young children recruited from India 
Older children recruited from India . 
Local Recruits .... 


19 
16 

9 
16 


I 
3 
5 
8 


5 
18 

55 
5° 



In other words, the children with enlarged spleen are mainly 
the local recruits, who probably brought their spleens to the 
estate, and the older children, who had been many years on 
the estate ; while few of later arrivals have contracted the 
disease. Indeed, the children who had been born on the 
estate were a striking picture of good health, and might well 
have entered for any baby competition. Eleven children were 
born in 1919; the only one, who died, did so after going to 
Malacca. 

The success of the mixed oils in controlling A. maculatus was 
so striking that Mr Gilman introduced its use on Rasak Estate 
and later on Bukit Jelutong Estate ; Mr Harrison, on Midlands 
Estate ; Mr Hendrie, on Ebor, S. Neibong, and Tanah Bahru 
Estates. Now it is widely employed all over the Peninsula, 
with great advantage to the community. 

How Oil Acts. — The action of mineral oil on larvae is by 
no means fully understood. The original idea was that, 
forming a film on the surface of the water, it cut off the 
larvae from their air -supply and killed them by suffocation. 
Another idea is that some oil penetrates their air-tubes, and 
poisons them directly ; while some hold that the oil, or at 
least some poisonous substances in it, are dissolved in the 
water, and poison the tissues of the larvae. Yet another 
view is that the oil lowers the surface tension of the water, 
so that larvae can no longer support themselves at surface. 

However the oil acts, anopheles larvae in this country are 
highly susceptible to its effects, and die more rapidly after 
contact with it than any other larvae. 

Apart from any direct action the oil may have on the insect, 
there is probably an important indirect action. Previously, 
I mentioned the appearance of a " green slime " on the bottom 
of the ravine following on the application of the oil. It consists 
of an alga, the filaments of which are closely " felted " or 
matted," and attached to the stones or sand forming the bed, 



190 OILING 

of the stream. The filaments are much finer than those of the 
ordinary alga that one finds in a pool of clear water in a 
ravine; and the "felting" differs from the "loose floating 
tangle " of the ordinary alga. When a clear pool containing 
the ordinary floating alga is "oiled," the alga dies; it becomes 
a dark green mass, in which the individual filaments are 
unrecognisable. In its place appears the " felted " alga ; and 
whenever a ravine is thoroughly oiled this alga appears. It 
is a test by which to know if oiling is properly carried out. 
Long before I had used oil in ravines I had noticed that the 
presence of the " felted alga " meant the absence of A. maculates, 
and I had noticed its association with pollution of the water. 
For example, on an estate there were four ravines, identical 
as far as the eye could see. At the head of one there was 
a well where clothes were washed ; that ravine alone contained 
" felted alga." On no occasion was A. maculatus taken in it. 
In the other three ravines, which were not polluted, and did 
not contain the " felted alga," the insect flourished. Three 
bungalows, one on each of these three ravines, were so 
malarious that they were pulled down ; a bungalow on the 
other ravine was much less malarious, and is still inhabited. 
This was observed before oiling was used in ravines. 

Some ravines are to be found where the "felted alga" is 
growing freely, although no pollution apparent to the eye 
takes place, and no oiling has been done. On one occasion 
I found the " felted alga " in a ravine, and tracked it upwards. 
The ravine branched, and the alga followed only one branch, 
in which it could be found as far as a log of a newly-cut timber 
lying in the water. Beyond that the alga could not be found. 
I can give no explanation of its appearance ; but took possession 
of a piece of the wood. In ravines where the pollution is 
extreme, where, for instance, the whole discharge from a rubber 
factory is poured into a small stream, the aquatic growth will 
be found to differ in different parts of the stream. Nearest 
the factory, the growth may consist of dense pendulous fawn- 
coloured masses, composed of colourless filaments containing 
no chlorophyl ; lower in the ravine this is replaced by the 
" felted alga." 

A full study of the subject 33 is necessary, and may well 
give us an entirely new method of controlling malaria. It 
is a part of the subject treated in Chapter XIX., entitled 



SOME PRACTICAL POINTS 191 

" On the Possibility of altering the Composition of Water and 
the Anophelines Breeding in it." 

Some Practical Points. — The " Liquid Fuel " used in this 
country is, I understand, not " crude oil," but a refuse after 
some of the more volatile oils have been distilled off. Its 
composition varies greatly. Some consignments, without any 
admixture with kerosine, can be used in a sprayer, and will 
give a film which spreads at once on striking the water ; other 
consignments may require the addition of one part of kerosine 
to eight parts of " Liquid Fuel." 

It is best applied through a knapsack sprayer, of which 
there are several well-known makes, such as the " Four Oaks " 
and the " Vermorel." The " Four Oaks " is usually supplied 
with rubber valves, which perish in twenty-four hours after 
contact with oil ; but leather valves are supplied if asked for. 
In Panama the "Meyer's Sprayer "was considered best. The 
valves are metal, and give a minimum of trouble. This sprayer 
has an overhead lever action which is less fatiguing than the 
side action of some other sprayers ; and it has the additional 
advantage that, by a simple adjustment, the lever may be 
turned to either side and used by either hand, which gives 
some relief in the day's work. 

The oil is sprayed particularly on to the edge of the 
streams, and for a foot or two up the banks. This destroys 
not only larvae, but all grass and ferns growing on the banks. 
It saves the costs of weeding these, and the cost is considerable ; 
in addition the brown, discoloured bank shows the oiling has 
been properly done : the presence of living vegetation indicates 
lack of oil. 

I do not encourage the use of barrels dripping oil on to 
a stream. Oil so applied fails to reach the side pools springs, 
and other small but important breeding-places in a ravine. 
Drip barrels are, by themselves, insufficient, and may lead 
to a false sense of security ; when spraying is properly done, 
they are unnecessary. I believe there are no drips on the 
estates under my care. 

For each man spraying, two men are employed to carry 
oil. On a large estate there are usually several depots to 
which the drums of oil are carted ; this reduces the distance 
that the coolies have to carry oil to the sprayer. 

The cost of oiling an estate varies according to the number 



192 OILING 

of acres of ravine or swamp in it, the cost of the oil, and 
the cost of labour. The cost of both oil and labour have 
increased during the last year ; but from $200 to $600 a month 
is the cost at the present time on different estates. 

A Comparison of Subsoil Drainage and Oiling.- — Both oiling 
and subsoil drainage being effective against A. maculatns in hill 
streams, it may be asked which is the better of the two. A 
simple answer cannot be given ; each has certain advantages 
over the other. 

Oiling has two great advantages. The first is that it 
can be brought into action over a whole estate in a week 
or less, utterly destroying every anopheles larva in the ravines ; 
and many adult insects that return to their places in the ravines 
perish also when they alight on the oil. So it comes about 
that the complete control of mosquitoes on an estate, which 
is oiled, is rapid, and measured by a period of a few weeks. 

The other great advantage is that there is no large 
capital outlay for oiling, such as is required for subsoil drain- 
age. The cost of oiling is a permanent annual charge, and 
will not diminish materially, if at all, with the passage of 
time ; but, generally speaking, the weekly, monthly, and 
annual cost is not heavy when compared with that of sub- 
soil drainage. This is not unimportant, for malaria often 
causes heavy loss to an estate, and puts it in straightened 
circumstances. 

Subsoil drainage, on the other hand, may involve a heavy 
capital expenditure. Another disadvantage is that it may take 
many months to drain the ravines, and during this time the 
people suffer from malaria, carried by the anopheles breeding 
in the still undrained ravines. This disadvantage can be 
overcome by "oiling" the whole estate during the execution 
of the drainage work. 

Drainage has a great advantage over oiling, in that it 
requires less European supervision. One can see at a glance 
in walking over a ravine whether or not it is dry ; but one 
cannot check the work of the oiling coolie so easily. 

In reality, however, there is no antagonism between drainage 
and oiling. Oiling should supplement drainage when necessary. 
In many very steep places on an estate it will be easier to 
oil than drain ; such, for instance, as steep granite slopes. One 
would choose oil in preference to pipes in a wide ravine full 




Fig. 55. — Meyer's Sprayer. 




Fig. 56. 
A well-oiled Ravine, with the sides of the drain free from grass. 



[To face page 192. 



SUBSOIL DRAINAGE AND OILING 193 

of good rubber trees. In a narrow ravine one might oil, pipe, 
or allow jungle to grow up, depending on the particular zone 
of the country in which the ravine was situated, the amount 
of silt coming from the hills, and other local circumstances. 
In all cases, one would begin the control of malaria by oiling ; 
and oil could be used as a "test solution" to determine the 
exact area to be drained. 

Finally, I must emphasise, in the strongest possible 

MANNER, THE ABSOLUTE NECESSITY OF THE MANAGER, OR 
ASSISTANT, IN CHARGE OF THE OILING, REGARDING THIS 
WORK AS NOT SECOND IN IMPORTANCE TO ANY OTHER ON 
THE ESTATE. THROUGH FAILURE TO DO SO, OILING IS 
SOMETIMES NEGLECTED, WITH SERIOUS LOSS BOTH OF LABOUR 
AND OF CROP. 



CHAPTER XVIII 

SOME OTHER EXAMPLES OF HILL CAMPAIGNS 

It is impossible, in the space available, to give details of all the 
hill estates upon which I have been asked to advise, and for 
which I have suggested health areas. Not all, by any means, 
have been successful. At the beginning, before I could speak 
from experience, the area suggested was 20 to 30 chains in 
radius for pipe drainage. This is not sufficient in most places 
to eradicate malaria ; although it will improve health. It is 
clear now that in dealing with A. maculatus, probably the 
most efficient carrier of malaria in the Peninsula, and where 
that mosquito is present in large numbers in much broken hill 
country, an area of at least 40 chains in radius is required. It 
must either be drained by pipes or oiled. 

Another cause of failure was the difficulty some managers 
evidently had in grasping the right way to lay the pipes, and 
in learning how to look after the ravines once they were 
drained. In some places where damage done by storm water 
was not repaired at once, the whole system became blocked by 
silt, or it was extensively torn up. The early days had its 
quantum of scoffers : oiling they sneered at ; naturally they 
took little interest in or care of an engineering system which 
calls for both intelligence and diligent supervision. Under 
such, anti-malaria measures made little progress, or were 
failures. 

It was no small disadvantage that after starting a scheme 
in some distant part of the Peninsula, I could only visit it at 
long intervals, and so was unable to supplement what was 
sometimes deficient in the manager. 

But ten years have passed since I pointed out the special 
difficulty of anti-malarial work in hill land ; both subsoil 
drainage and ravine oiling have proved themselves capable 
of controlling A. maculatus and its malaria ; each year sees 

104 



GLENMARIE ESTATE 



195 



their extended use ; indeed, on few malarious estates are anti- 
malarial measures of some sort not in force ; and the result is 
seen in the general lowering of the death rates of estates 
throughout Malaya. 

In this chapter I propose to give simply the plans of several 
estates, with, in a few instances, remarks on the reasons which 
guided the selection of the health area. They may be of use 
to those called upon to deal with similar conditions. 

Glenmarie Estate. — This is one of the oldest estates in 




GLENMARIE ESTATE 



Fig. 57. — Plan of Glenmarie Estate. 

the country ; it has always been malarious. Indeed, so much 
did malaria trouble it, that a former proprietor built " Turkish 
baths" in order to "sweat" fever out of coolies. It was 
only tried once, as the coolie was brought out dead. The 
building still remains — as a motor shed. 

To improve health, a number of lines were abandoned in 
191 1, and all were concentrated on a central area. At first 
some 20 chains were drained by pipes ; the work was excellently 
done by Mr Solbe. It produced a marked improvement in 
health, and enabled the estate to establish a force of 
Malayalees, a tribe of Indians highly susceptible to malaria, 

P 



196 SOME OTHER EXAMPLES OF HILL CAMPAIGNS 

and one which cannot live in untreated ravine land. The 
20 chain area did not, however, give the required result, 
so in 1917 the area was extended, partly by piping, partly 
by oiling ravines. Health still further improved, so that in 
1919 the average monthly malaria admission rate was 3 per 
cent. 

The table on page 197 shows the death rates. 




"D.J." ESTATE 



Emery Walker Ltd. so 



Fig. 58.— Plan of Estate " DJ." 

Estate " JM" — The difficulty on this estate was that swampy 
land, under different ownership, came within the circle. The 
coolie lines were well built, and I hesitated at the time to 
condemn them on account of their site. Now I would not 
hesitate to do so, and would strongly recommend the alterna- 
tive site proposed. 

Estate "JC." — Fig. 60 shows the buildings of the estate 
widely scattered. The best course would be to concentrate 



ESTATE "SC" 



197 



them about the spot marked " Central Site." The ravines 
should be oiled or drained by pipes within the half-mile circle, 
and outside the circle at the heads of ravines A, B, and C. 
Alternative sites would be found lower down the main ravine. 



Year. 


Death Rate 
per mille. 


Remarks. 


1910 
1911 
1912 

1913 
1914 

1915 
1916 
1917 
1918 
1919 


16S 
126 
103 

51 

59 
51 
40 

65 
173 

35 


Subsoil drainage begun 1911. 

Area extended. 

Includes influenza, 47 deaths. 



Estate "SC." — The history of this estate "SC" is of 
unusual interest. In 1909 I visited it, recommended that the 
coolie lines in ravine 4 be abandoned, and selected the site on 
the bank of the river, which is heavily polluted by mining silt. 

The bank of the river is in places swampy, and there are 
numerous abandoned mining holes filled with water. In the 
ravine site the mosquito was A. maculatus, the most efficient 
carrier of malaria in this country ; and along the river bank 
and in the mining holes the mosquitoes were A. barbirostris, 
A. sinensis, A. fuliginosus var. nivipes, and A. rossi, which are 
poor carriers, if they carry at all. The removal of the lines 
led to a great improvement in health; so that in 1913 the 
average Indian labour force was 857, no fewer than 816 new 
coolies were introduced, yet the death rate was only i8>6 per 
mille. This low rate would be impossible with so large a 
labour force, if malaria were present to any extent. 

The good health continued until August 1914, when malaria 
broke out severely; and in January 191 5 I again visited the 
estate. At this visit, I was unable to determine the cause of 
the malaria; but in a subsequent visit in June, A. maculatus 
was discovered breeding in a branch of ravine 2 coming from 
an adjoining estate. The ravines 2 and 3 did not contain 
A. maculatus, and were heavily coated with the felted alga * 
referred to in the Chapter on Oiling. From 1912, when the 
adjoining estate was opened, to 1914, the branch of ravine 2 
* This was not due to oiling in this instance ; but was a natural growth. 



198 SOME OTHER EXAMPLES OF HILL CAMPAIGNS 

was probably unfit for A. maculatus on account of the silt 
from the clearings ; by 1914 the silt decreased, there was less 
decomposing vegetation, so the water probably became pure 
enough for A. maculatus. Oiling this ravine rapidly improved 
the health, and it has continued good since. 





A " J 

* \ 

/ at<^® x At *■ i-a^^JA 

/ / ■ •- v^ / K 

J* Bridge / °^W<^ 


M." ESTATE 


/ \ZJT l * 


Proposed 

., Site V/ 

Alternative 




) 






\ Ravinel^jf- 






\ /r" 






j 











Emery Walker Ltd. sc, 



FIG. 59.— Plan of Estate "JM.' : 



ESTATE "JC." 

The following table tells its own tale : — 



199 



Year. 


Labour Force. 


Death Bate. 


I9I3 


857 


18 


1914 


561 


53 


1915 


427 


74 


1916 


422 


4 


1917 


512 


7 


1919 


614 


11 



An examination of forty-one children in 191 5 on the river 
site showed a spleen rate of 43; in 1920 there were no 
children on the same site, with a spleen rate of 5. 



"JC." ESTATE 




Fig. 60.— Plan of Estate "JC." 



Emery Walker Ltd. sc 



A few coolies live in a set of lines in Field XI., on a ravine 
similar to that from which the labour force was removed in 
1909. In 191 5 there were twenty-two children, with a spleen 
rate of 100 ; in 1920 there were four children, with a spleen 
rate again of 100. This shows that the ravines in the centre of 
the estate still remain intensely malarious ; in strong contrast 
to the site on the swamps next the river. 



S.C." ESTATE 




Fig. 63.— Plan of Eslate "SC." 



hnieryW'.ilker Lt.l. sc. 




Fig. 6i.— Estate "SC." 
Photograph from point marked "A" on plan looking towards coolie lines, just 
seen in the distance ; the great mining holes and swampy nature of the site selected are 
well seen. 




Fig. 62.— Estate " SC' 
Photograph from point marked " B " on the plan. The coolie lines are seen on the 
flat land. The river runs between the observer and the lines ; one of the numerous 
abandoned mining holes is seen just across the road. [To face page 200. 



CHAPTER XIX 

ON THE POSSIBILITY OF ALTERING THE COMPOSITION OF 
WATER AND THE ANOPHELINES BREEDING IN IT 

(1920). — This chapter has been reprinted as it appeared in 
the previous edition, except for some minor alterations in 
composition and changes in the names of mosquitoes to those 
now generally in use. 

(1909). — It has long been established that mosquitoes, 
including the anophelines, exercise discrimination in the selec- 
tion of water in which their larval stage is passed. Each 
species prefers its own special type or character and quality of 
water as a breeding-place. Some have a wide range, others 
are peculiarly selective. A. maculatus is one of the latter. In 
Malaya it is found exclusively in hill streams, and in the 
springs which feed these. I consider that the eggs are laid 
in, and that the larvae prefer, the shallowest waters ; indeed 
they are most numerous in ground with so little water on it 
that, in order to take the larvae, it is often necessary to make 
an excavation in the earth into which the water from the 
surrounding ground flows, carrying the larvae with it. As 
these springs are very common at the head of a ravine, the 
presence of this mosquito in them probably accounts for the 
well-recognised danger of living at the head of a ravine. The 
old explanation for this was that mists were carried up the ravine, 
and naturally struck with special force those living at its head. 

From these springs the larvae are carried down the streams ; 
but they cannot be entirely washed out, even by the strongest 
currents or rains. I have found them in a drain after a 2-inch 
shower. When one attempts to take them they often wriggle 
completely out of the water on to the damp ground. I have 
watched them at play in a clear pool at the foot of a rock, 
down which water was flowing with considerable force, since 
the rock sloped to the pool at an angle of 45° and its face was 
a foot long. The current of water was still further increased in 

201 



202 ALTERING THE COMPOSITION OF WATER 

strength by the rock being funnel-shaped, and all the water 
coming down the face was gathered into a solid stream as it 
entered the pool. The larvae were playing, not exactly like 
trout, head to stream, but were floating round in the current, 
and every now and then one would swim right into the stream, 
up it for a short distance, and then hang on to the side of the 
apparently bare rock in the full strength of the current.* 

As A. maculatus is never found on the flat land, it is obvious 
that this mosquito requires water of a special character ; such as 
water well aerated and quite free from vegetable decomposition. 

In May 1909, having accepted an invitation from the late Mr 
C. Malcolm Cumming, Chairman of the Planters' Association of 
Malaya, to visit a Tamil settlement which he had successfully 
established, I motored into Negri Sembilan and saw the padi 
swamps, rice-fields, or sawahsj- there. These consist of valleys, 
the whole bottom of which have been rendered flat, so that 
they can be irrigated by the waters coming down the valleys. 
They seemed to me ideal breeding-places for anophelines, 
and I asked if they were unhealthy. I was assured that the 
inhabitants were extremely healthy, and that malaria was 
unknown. It occurred to me then that the process of padi 
cultivation must alter the composition of the waters in some 
way, so that what I should regard as the normal inhabitant of 
the valley stream, namely A. maculatus, had been driven out. 

The following day, when passing an estate, Mr Cumming 
informed me that the estate had been healthy until Tamils 
had been introduced, and since then had been extremely 
unhealthy. I remarked that the valley through which we were 
passing was very swampy, and he then told me that it originally 
had been sawah, but that the Malays now were employed on 
the estate, where they got better wages. 

It appeared to me that if there was any truth in the state- 
ment that sawahs were healthy, then the abandonment of 
the sawah, and not the introduction of the Tamil coolie, 
was responsible for the outbreak of malaria on the estate. The 
idea was that by abandoning the sawah, the A. maculatus 
had been enabled to return to the valley. It was obvious, too, 

* Dr Lamborn is publishing an interesting paper on the hooked caudal 
hairs of larvae. 

+ " Padi " and " sawah " are Malay words, meaning rice and rice-field 
respectively. 




Fig. 64. — Krian Irrigation. 
A Main Channel. 




Showi 



Fig. 65. — Krian Irrigation. 
; the grassy sides of a subsidiary drain and the flooded, yet healthy, land. 

[To face page 202. 



KRIAN IRRIGATION PADI FIELDS 203 

that it might be a method of treating ravines on rubber estates 
where the drainage was difficult, or where weeding was so 
expensive that it might be an economy to abandon the ravine, 
if this could be done without impairing the health of the labour 
force on the estate. The matter appeared to be of importance 
economically, and called for investigation. 

I therefore spent that night on the edge of a sawah. In 
the evening three anophelines were taken — one A. fuliginosus, 
one A, sinensis, and one A. rossii. Under ordinary circumstances, 
I should have expected to find at least one A. maculatits. I 
learned that this sawah was considered healthy. In the morn- 
ing I examined fifty Malay children at Kampong Batu Malay 
School, of whom twenty (or 40 per cent.) had enlarged spleens. 

So far these results appeared to bear out my conjecture, 
but I had no opportunity of further investigation until August, 
when I went to the Krian Irrigation Padi Fields, and also 
to those at Bukit Gantang. I was only able to spend a week 
on the work at that time, and was unable to return to finish 
it until November. 

The investigation consisted of an examination of the 
children and of the species of anophelines breeding in the 
waters, and found in the houses in the two places. Although 
both were padi swamps, the most extraordinary difference 
in the health of the two places was discovered, and a difference 
in the species of anophelines was also found. 

Krian Irrigation Padi Fields. — This irrigation scheme, 
carried out at the cost of about \\ million dollars, was completed 
in 1906, and was at once a financial success. It enabled 
the people to reap a good crop in a dry year, when their 
neighbours, outside the irrigation area, were suffering from 
want of water. The area irrigated is about 60,000 acres. 

The water-supply is from two rivers, the Sungei Merah and 
the Sungei Kurau, which are dammed at a pass in the hills, 
so that by overflowing their banks they spread over ten square 
miles of jungle. The effect of the constant water on the jungle 
has been to kill it out slowly, and in passing along the railway, 
which crosses the reservoir, one sees comparatively few of the 
larger trees now alive, while many dead ones are still standing. 

These rivers have already traversed considerable distances 
before they reach the impounding reservoir, but the waters of 
both have originally come from the hills. 

From the impounding reservoir the water is led by the usual 



204 ALTERING THE COMPOSITION OF WATER 



Main Range of Peninsula 



G BIONG 
3991 




Parit 
Buntar 



T *> 



T s 



OF MALACCA 



KRIAN IRRIGATION 

8 



Scale of Miles 
01234 



FIG, 66, — Kriaiv'Irrigation Map, 



EmeryWalker Ltd. St 



HEALTH OF CHILDREN AT KRIAN 



205 



canals, and after flowing over the land is led off by drains to 
the nearest rivers as will be seen from the map. 

Healtli of Children. — During my two visits I examined 
304 Malay or Tamil school children and 47 estate Tamil 
children ; and the late Dr Delmege, the Government Medical 
Officer, kindly furnished me with the figures of 367 school 
children whom he examined. Out of the total 718 examined, 
only 20 (or 2-7 per cent.) had enlarged spleen. 

The details of the examinations are as follows : — 



Observer. 


Place. 


Number 
Examined. 


Number 
Enlarged. 


Per cent. 
Enlarged. 


Dr Delmege 


P. Buntar— 










Malay boys 


52 


O 


0.0 




11 girls 


39 


O 


0-0 




English, mixed . 


28 





0-0 




Sungei Star 


47 


O 


o-o 




11 ... 


31 





o-o 




Sungei M. Aris 


59 


2 


3-3 




„ Labu 


28 


3 


IO'O 




Titi Serong 


57 


5 


87 




Jalan Bharu 


26 


2 


7-6 


Dr Watson 


Bagan Serai — 










Malays .... 


66 


3 


4-5 




Tamils .... 


34 





CO 




Telok Maiden . 


7i 


2 


2.7 




Jin Heng Estate — 










Tamils .... 


47 





O'O 




Sungei Siakap . 


65 


3 


4.6 




,, Bharu . 

Grand total . 


68 





0-0 


718 


20 


2-7 



A reference to the map will show that these examinations 
cover practically the whole district, and can be considered 
quite representative of it. They show conclusively that this 
irrigation area is to a striking degree free from malaria. This 
is the general idea, and Dr Delmege writes me as follows: — 
" I quite agree with you that there is very little, if any, malaria 
contracted in the padi fields." 

The Anophelines of Krian Irrigation. — The anophelines of 
the Krian District were found to be — 

A. rossii, A. sinensis, 

A. kochii, A. barbirostris. 

The two last-named mosquitoes are found breeding freely in the 
irrigation channels and in the padi-fields. They are also found 
in the houses, where they feed freely on the inhabitants. 



206 ALTERING THE COMPOSITION OF WATER 

The low percentage of infected children in a place in which 
adult anophelines are so abundant is strong evidence that 
these species do not carry malaria ; or, if they do, they act 
as extremely inefficient hosts for the parasite. The fact that 
the percentage of children with enlarged spleens is practically 
the same as in Klang, and on the healthy estates, where a 
history was obtained of the affected children, mostly immigrants, 
who had suffered from malaria before their arrival, makes it 
extremely probable that the affected children in the Krian 
District had contracted their malaria outside its limits. 

I was unable to make any investigations into the health of 
the children on the estates in the Krian District beyond that 
of the one mentioned, which was on the opposite side of a 
road from the irrigation area, and where the spleen rate of the 
forty-seven children was found to be nil. An examination, 
however, of the death rates of the estates on the flat land 
of Krian is so low that malaria can hardly be a serious 
consequence. One estate, however, which is shown to be on 
the edge of a Government forest reserve has a death rate 
of ioo, evidence that malaria is to be found near to the jungle 
in Krian as in Klang, and that opening of the land gives 
freedom from malaria there also. 

Bukit Gantang Valley Rice-fields. — About 10 miles south- 
east of the Krian Fields the main range of the Peninsula is 
cleft by a valley leading to what is locally known as the Bukit 
Gantang Pass. (Bukit in Malay means a hill or mountain). 
The valley runs in some 5 miles, and its mouth, 2 miles wide, 
has Chankat Jering and Bukit Tebok on the north and south 
sides respectively. From side to side, from end to end, the 
valley is a sea of padi, in which are studded Malay kampongs, 
like the " islands " of an archipelago. There is a considerable 
Malay population among the hills and on the "islands." 

An examination of the children living at the foot of 
the hills showed that they were suffering severely from 
malaria. 

In thinking over the idea of excluding certain species by 
altering the composition of the water, it occurred to me, that, 
if an experiment were to be carried out, it would be best to 
avoid housing the coolies near the foot of the hills and sides of 
the ravines. Where A. maadatus were most likely to breed, 
would be the places to avoid in housing the coolies ; and if an 




Fig. 67.— Bukit Gantang Valley. 

The photograph shows the padi (rice) fields in the foreground and Malay houses 
along the foot of the hill on the left. On the right the valley widens out, and the 
small clump of trees is the beginning of the series of kampongs which I have likened 
to " Islands " in a sea of padi. 



[To face page 206. 



BUKIT GANTANG VALLEY RICE-FIELDS 207 

island in the middle of the padi could be made, there the 
coolies would enjoy the best health. 

Having ascertained that the children on the edge of the 
hills were very unhealthy, I at once realised that in this valley 
the conditions of the experiment I had thought of were actually 
to be found on the most magnificent scale. The valley being 
2 miles wide, the possibility of mosquitoes flying from the sides 
to the centre of it in such numbers as to carry malaria was 
excluded. It remained, therefore, to ascertain the percentage 
of children infected on both sides of the valley and in the 
centre, and to determine the species of the anophelines. 
Starting at Chankat Jering the Malay schools were examined. 

At Chankat Jering fifty-one children were examined, of whom 
twenty-two (or 43 per cent.) had enlarged spleens. Two miles 
farther up towards the Pass, Jelutong school was examined. 
Of the thirty-nine children, seventeen (or 43 per cent.) had 
enlarged spleens, and several others had fever at the time of 
the examination without having enlargement of the spleen. 

Still nearer the Pass, Bukit Gantang school was found to 
contain fifty children, of whom twenty-five (or 50 per cent.) had 
enlarged spleens. 

Thus out of 140 children living at the foot of the hills and 
on the edge of the padi, no fewer than sixty-four (or 457 per 
cent.) had enlarged spleen, strong evidence of the prevalence of 
malaria. While at Simpang, 2 miles from Chankat Jering, 
out of thirty-three children examined at the school only three 
(or 99 per cent.) had enlarged spleens, showing that as we 
passed from the hills malaria was less severe. I next examined 
the Bendang Siam school in the middle of the valley on the 
road running south towards Bukit Tebok. On this road, in 
the 2 miles where it runs through the padi swamps, there 
are no fewer than ten bridges, each indicating a small stream 
running down the valley. In the school of thirty-one children, 
nineteen (or 61 per cent.) had enlarged spleens. There were 
sixty-two on the register, but, as examination was made at 
the time of the fruit season, the attendance at the school 
was then about sixteen daily, and three visits had to be 
paid before the thirty-one children were obtained for examina- 
tion. In order to broaden the basis of the observation, and 
at the same time to obviate error due to the attendance of 
children from the south side of the valley, I examined 
fifty children in the houses of the " Islands." I was accom- 



208 ALTERING THE COMPOSITION OF WATER 

panied and assisted in this by Dr Bryce Orme of Taiping, 
and we spent the best part of a day in going through the 
valley, which consisted of patches of dry land and of padi 
swamp irregularly mixed together. On the dry patches the 
Malay plants his house and his trees, and in the swamp grows 
his padi. Of the fifty children in the " Islands," eleven, or 
22 per cent., had enlarged spleens. Only one case of fever 
was found among the fifty children, and the inhabitants 
insisted that fever did not trouble them. The children found 
in the houses were mostly younger than those at school. It 
was thus obvious that both at the sides and in the centre of 
the valley malaria was present in serious amount among the 
children ; but that the adults, presumably from having had 
the disease during childhood, were now immune, and con- 
sequently regarded the locality as healthy. 

Apart from the evidence of the children, the history of the 
making of the railway, which runs over the pass, was one of 
severe malaria, especially at Ayer Kuning and Bukit Gantang, 
where large cuttings had been made. 

I may remark here that the spleen rates of Malay children 
in their kampongs is not comparable with that of Tamil immi- 
grants on an estate, since among the latter the non-immune new 
arrivals of all ages up to ten form a larger proportion of the 
total population than do the new born of the Malays. While 
a number of the Malays in the higher ages will already have 
acquired immunity, and lost the enlargement of the spleen, the 
Tamils, at all ages, will still be suffering from the disease. 

Places newly populated by an immigrant coolie population 
showing a spleen rate of ioo may really differ considerably in 
the amount of malaria present. 

Anophelines of Bukit Gantang Valley. — During the four days 
(16th to 19th November, 1909), twenty-six adult anophelines 
were taken in the houses of the " Islands," or Kampong Paya 
and Bendang Siam, as the places are locally known. They 
were the following : — 

A. rosii . . . . 10 

A. aconitus . . .6 

A. barbirostris ~\ 

A. sinensis J 

A. iiDibrosus . . . . .1 

26 



ANOPHELINES OF BUKIT GANTANG VALLEY 209 

The larvae of these mosquitoes were found breeding as 
follows: — Enormous numbers of A. barbirostris and A. sinensis 
were in the padi-fields. A. rossii were in pools near to the 
houses. A. aconitus was found breeding in a stream running 
through the padi swamps and in swampy grass through which 



0. Hunt/ 
4750.d 



rAOtflELDS A- 

HILL \45S8 




Scale of Miles 

I 2 



BUKIT GANTANG VALLEY 



Emery Walter Ltd. sc. 



Fig. 68.— Map of Bukit Gantang Valley. 



210 ALTERING THE COMPOSITION OF WATER 

water was flowing slowly. Larvae of A. umbrosus were not 
found. 

In addition, one specimen of A. fuliginosus was hatched 
from a padi swamp about a mile in from the road. 

In a set of coolie lines at Ayer Kuning, on the Chankat 
Jering side of the valley, three adult A. maailatus were 
caught in a few minutes. At Bukit Gantang village fifteen 
adults were taken in houses, of which fourteen were A. rossii or 
A. sinensis and one A. aconitus. In a stream flowing down 
from the railway at Bukit Gantang numerous larvae with 
simple unbranched frontal hairs were found in a backwater. 
These failed to hatch out. 

On the Bukit Tebok side of the valley in a house at the nth 
mile two adults were taken, one of which was A. barbirostris and 
the other A. fuliginosus. Larvae were taken in a spring at the 
edge of a swamp near this, with the characters of A. maculatus, 
but they failed to hatch out. While in a ravine running towards 
Bukit Tebok, numerous larvae belonging to the Myzorhyncus 
group, possibly either M. separatus or M. umbrosus, were found 
among the swampy grass. They, however, suffered, as did the 
other larvae, from the 200-mile journey to Klang, and failed to 
hatch out. A few miles further down this road, in the lines of 
a very unhealthy estate, ten A. maculatus were taken in half 
an hour. The estate is traversed by hill-streams. 

Table comparing the Anophelines taken at Bukit Gantang Valley 
and at Krian. 



At the foot of the Hills 

forming Bukit Gantang 

Valley. 


In the Rice Fields of 

Bukit Gantang Valley, 

" the Islands." 


In Krian Irrigation 
Area. 


Much Malaria. 


Much Malaria. 


No Malaria. 


A. maculatus. 
A. aconitus. 
A . fuliginosus. 
A. umbrosus. 
A. barbirostris. 
A, sinensis. 
A. kochii. 
A. rossii. 


A. acorn tus. 
A . fuliginosus. 
A. umbrosus. 
A. barbirostris. 
A. sinensis. 
A. kochn. 
A. rossii. 


A. barbirostris. 
A. sinensis. 
A. kochii. 
A. rossii. 



Reviewing these facts, we may conclude that in the hill 
ravines and springs of Ayer Kuning and of the main range 



OBSERVATIONS OF IRRIGATION PADI-FIELDS 1211 

generally A. maculatus is acting as an efficient carrier of 
malaria, but the entire failure to take it in the " Islands," 
when it was so easily taken at the sides of the valley, warrants 
the conclusion that it does not spread far from the hills, and 
does not breed in the padi swamps. It is, however, evident 
that some of the other anophelines found there are carriers 
of malaria. A. rossii and A. barbirostris and A. sinensis can 
be excluded, since their presence in Krian caused no malaria. 
Suspicion must, therefore, rest on the other three, namely, 
A. umbrosus, A. fuliginosus and A. aconitus* '• The first of 
these is the great carrier of the flat, undrained jungle-land 
in Klang. It is easily seen and captured, as it is a large 
mosquito. As only one was taken, it is probably not the 
important carrier at Bukit Gantang rice-fields. A. fuliginosits 
is closely related to A. maculatus, and A. aconitus is one of 
the small black-legged Myzomia group to which A. funesta 
(the African carrier) and A. culicifacies (the India carrier) 
belong. The time at my disposal did not permit me to 
complete the investigation of this point. 

Conclusions from the Observations of the Krian and Bukit 
Gantang Irrigation Padi-fields. — Incomplete though they be, 
the investigations have established certain important points. 
These are : — 

(i) That the conversion of ravines into ordinary sawahs 
would not improve the health of a rubber estate. 

(2) That these sawahs or padi swamps at the foot of 

hills or in ravines are extremely malarious, and that, 
although the adults appear to enjoy good health, 
the immunity from malaria which they possess has 
been acquired through their having suffered from 
malaria when children. 

(3) That the estate in Negri Sembilan, which was supposed 

to become unhealthy on the introduction of the 
Tamil coolies, had always been unhealthy ; and the 
adult Tamils had only suffered in the same way as 
the children of the Malays and other newcomers did. 

(4) That vast areas may be put under wet padi or irrigated 

* Dr A. T. Stanton has since then proved A. aconitus to be a natural 
carrier of malaria. It is probably the chief carrier in the rice-fields in 
valleys in the Peninsula. 

Q 



212 ALTERING THE COMPOSITION OF WATER 

land without causing malaria was seen from 
Krian. 

(5) That padi land at the foot of hills irrigated by the 

water from the hills is very malarious. 

(6) That different groups of anophelines are found in (a) 

the water of hill-streams; (b) the water close to the 
foot of the hills ; (c) the water at some distance from 
the hills. 

(7) That on the difference of species of these anophelines 

depends the presence or absence of malaria. 

It is not my purpose to record speculation here, but rather 
facts regarding malaria which have come to my notice during 
the past nine years. I cannot, however, pass from this subject 
without pointing out the great hope which these observations 
raise of dealing with malaria on new lines. 

Hitherto the attitude towards the malaria of rice-fields, 
and all rice-fields were supposed to be malarious, has been 
that rice and malaria are inseparably connected. Rice, being 
the staple food of many millions in the tropics, must be grown. 
The choice appeared to be starvation or malaria; this is of 
course really no choice, since people must always run the risk 
of disease rather than starve. 

The only attempts to destroy malaria where it was 
impossible to remove the breeding-place entirely by destruc- 
tion of the larvae, have been by the use of petroleum and 
by the use of certain poisons put into the water. The Italians 
favour an aniline dye. 

The cost of such applications, on the very large scale which 
would be required for rice-fields, prohibit their use. 

Very powerful larvicides are infusion of tobacco leaves, and 
the powdered flowers of the Dalmatian chrysanthemum. But 
here again expense prohibits their use. Daniels experimented 
with the tuba root— Derris eliptica — but even if it could be 
applied on a very extensive scale, it is doubtful if it is not too 
comprehensive a poison, since it poisons fish, and as Daniels 23 
says, "few forms of animal life are unaffected." Such wholesale 
poisoning would probably interfere with the equilibrium of life 
in the padi-fields and produce consequences of an unwished- 
for character. 

But in Krian we have seen that nature has carried out in 




Fig. 69. 
A Rice-field in the coastal plain, near Malacca, not cultivated — not malarial. 




Fig. 70. 
A Rice-field in the coastal plain, near Malacca, under cultivation— not malarial. 

[To face page 212. 



EFFECT OF DRAINAGE ON ANOPHELINES 213 

the most successful way a method of altering the composition 
of the waters of the hills that the carriers of malaria no longer 
find it suitable for their existence, and malaria practically 
does not exist. I can imagine few greater benefits which the 
F.M.S. Government could confer on the Malay inhabitants 
than the discovery of the alteration which has occurred in 
the water, and its application to the numerous padi-fields of 
the Peninsula. It is not inconceivable that an industry might 
be found which required the maceration of a fibre, which, while 
changing the composition of the waters, might also provide 
the inhabitants with work. The culture of flax and hemp in 
Italy supplies a line upon which to work. A very large Malay 
population lives on the padi-fields of Perak, Negri Sembilan, 
and Pahang, who are now suffering from malaria in a severe 
form, unrecognised, it is true, since the children are the chief 
sufferers. This malaria must, in the course of generations, 
have left its stamp on the race, and possibly is responsible 
for the indolence of the Malay. Perhaps the Malay would 
become a less likeable character were he to acquire the energy 
of his Chinese competitor. 

In the past the struggle was perhaps no uneven one; for 
what the Malay lacked in energy and capacity for constant 
work, he made up for by force of arms. In a sense, peace has 
disarmed but one of the competitors ; and in the struggle for 
existence the Malay has now, unaided by the weapons of the 
past, to face. an alien foe full of the energy and strength of the 
colder North. 

If he is to survive in the struggle, it is essential that every 
obstacle be removed, and I can imagine no greater than 
malaria. Nor can I imagine how the West can more gloriously 
crown the benefits which it has heaped on the Malay in the 
past, than by the overthrow of the pestilence which saps the 
springs of his childhood life, and stamps the happy years of 
youth with pain and death. 

The Effect of Drainage on Different Species of Anophelines. — 
Now from the observation of species in Malaya and their 
behaviour to drainage, I would suggest it would be of 
practical importance to classify the anophelines of each 
country according to such behaviour. 

We have seen that A. umbrosus is only to be found in a 
pool without a current, while a current of water means its 



214 ALTERING THE COMPOSITION OF WATER 

destruction and disappearance. It can, however, breed in very 
weedy and obstructed ravine streams, as there the current is 
practically nil. 

A. karwari, on the other hand, is a pool-breeder, which 
prefers a gentle stream of fresh water flowing through its 
pool. Such pools are commonly found in the springs at the 
foot of a hill, and this I consider is the normal habitat of 
A. karwari. A ravine stream, if much obstructed by weeds, 
has so little current that it closely simulates the normal habitat 
of A. karwari, and so we find this mosquito in weedy ravines. 
Remove the grass and the mosquito disappears. There is 
then too much current for it. 

A. maculatus appears to prefer clear running water. There 
may be weeds, but they must not too seriously interfere with 
the free current of water. When disturbed it can leave the 
water, and it has powers of attaching itself to objects not 
possessed by pool-breeding larvae. These habits it doubtlessly 
has acquired ; and it is perhaps due to evolution that the 
species of anophelines (both Myzomyia and Nyssorhyncus), 
which breed in streams, are generally smaller than the pool- 
breeders, since thereby they offer less surface to the current. 
We have seen that, since this mosquito prefers a current of 
water, an open drain is its normal habitat, and open drainage 
fails to eliminate it and the malaria it carries. Open drainage 
can only eradicate malaria carried by pool-breeders. Therefore 
in Malaya, whether a hill stream be clean weeded or grassy, 
malaria remains, only the species of anophelines carrying it 
differs. 

A. rossii is at the opposite end of the scale from A. 
maculatus, and is a puddle-breeder. Since it is always found 
near to human habitations, the presumption is, it prefers pools 
soiled to some extent by human sewage. (Culex fatigans can 
breed in pure sewage, such as is found under a Malay house). 
On some estates, both on the hill and the flat land, this 
mosquito cannot be found. It, therefore, does disappear with 
thorough open drainage, although common enough in Klang 
town. 

We have thus a series of waters differing in quality and 
rate of current. Each water has its peculiar mosquito in- 
habitants, which have a limited range of waters in which they 
can breed. 



BREEDING-PLACES OF MALAYAN ANOPHELINES 215 






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216 ALTERING THE COMPOSITION OF WATER 

On whether the mosquito carries malaria or not, and on 
the ease or difficulty of eliminating the insect by drainage, 
depend the amount of malaria in a country, and the ease or 
difficulty of combating it. 

We see that in Malayan hill land, as long as there is an 
open system of drainage, malaria must remain, and in these 
hill lands malaria is as intense as anywhere in Africa. 

On the other hand, by good fortune, A. rossii — which only 
perfect surface drainage can abolish — does not carry malaria; 
and hence, as Daniels points out, Malayan towns do not suffer 
from malaria so much as African towns, where A. costalis, a 
mosquito with breeding habits similar to A. rossii, carries the 
disease. Consequently, although A. costalis can be destroyed 
by open drainage, to eradicate malaria in Africa would require 
a more thorough drainage and upkeep of drainage, than is 
necessary on the flat land of Malaya* where mosquitoes like 
A. karzvari and A. umbrosus are the carriers. 

Finally, I would urge that our knowledge of the prevention 
of malaria would be materially advanced if more attention were 
paid to the places where malaria does not exist. A truer idea 
of the part played by anophelines will thereby be obtained, 
and a less pessimistic view be taken than is often the case. 

* 1920. — A. ludlowi is a carrier of malaria in the flat land of the Malay 
Peninsula and elsewhere in Asia. It has been shown, however, that the 
thorough open drainage required to eliminate it is well within the range of 
practical sanitation ; so there is apparently no reason why malaria carried 
by A. costalis could not be controlled ; or if malaria were carried by A. rossii 
in Malaya, why it also could not be controlled. 



CHAPTER XX 

THE INLAND HILLS 

The Need for Research. — The more I thought of the observa- 
tions recorded in the last chapter, the more necessary it seemed 
there should be a thorough exploration of the habits and 
breeding-places of the anophelines ; for it was likely that out 
of such research important methods of controlling mosquitoes 
and malaria would be evolved. The subject was fascinating ; 
and in a public lecture, 24 given in Kuala Lumpur in 1910, I 
outlined my hopes : — 

" But when we came to work out the anophelines, it was 
found that different species were found in the middle of the 
swamp from those on the hills. Nature has, therefore, carried out 
a great experiment. There were three groups of anophelines : 
one on the hills, one in the rice-fields close to the hills, and a 
third lot in Krian far from the hills. Now, why do these vary? 
Clearly on account of something in the water, and it can easily 
be imagined that only a small change would bring the Bukit 
Gantang water to that of the Krian rice-fields, and then malaria 
would disappear from Bukit Gantang too. I believe that in 
this way a great anti-malaria method will be evolved, and I 
can look to the time when we will be able to play with species 
of anophelines, say to some "go," and to others "come," and 
abolish malaria with great ease, perhaps, at hardly any expense. 
Drainage schemes may become methods of the past, and future 
generations may smile to think of how their ancestors, who 
thought they were so clever, burned the house to cook the pig." 

At all times I was eagerly looking for facts that would not 
fit in with my theories of malaria in hill and flat land ; for 
exceptions either prove the rule, or throw new light on the 
whole subject. Above all, I sought a healthy town, village, or 
estate among the hills. 

The last chapter concluded with this remark : — 

" Finally, I would urge that our knowledge of the prevention 

217 



218 THE INLAND HILLS 

of malaria would be materially advanced if more attention were 
paid to places where malaria does not exist. A truer idea of 
the part played by anophelines will thereby be obtained, and 
a less pessimistic view of the prevention of malaria will be 
taken than is often the case." 

These two lines of thought dominated my researches in the 
following years. From 1909 onwards I was alert to discover 
some place among the hills from which malaria was absent, or 
even less in amount than would be expected ; for the discovery 
of a healthy town or village among the hills would at once 
give a solution of the problem. Although I found, on several 
occasions, swampy valleys in the hills with comparatively little 
malaria, I could not discover any place completely free from 
the disease. The significance of what had happened in Kuala 
Lumpur in 1906 and 1907, and of the observations of Mr Pratt, 
Dr Fletcher, and Dr Wellington, I had failed to realise. (See 
Chapter XXVI.). 

It was not, indeed, until Dr C. Strickland had been some 
time engaged in his research, and visited parts of the Peninsula 
to which I had never been, that he found the long-sought-for 
" happy valley." 

In May 191 2, Dr Strickland arrived in the F.M.S. to take 
up malaria research, and more particularly to study the biology 
of the anopheles in relation to malaria. With pleasure, I 
showed him all that I thought could help him, and we discussed 
the lines of research indicated above. 

In a memorandum to Government I suggested the following 
as his course of study : — 

"(1) Healthy, flat land (coastal belt); (2) healthy, wet land 
(Krian rice-fields) ; and (3) then working up from the coast 
into the valleys of Negri Sembilan, from what I believe healthy 
into what is unhealthy. There is much to be learned here, I 
am sure, for the undrained swamps in valleys are certainly 
in many places healthier than those that are clean-weeded. 
Why this should be is clearly an important question ? . . . The 
above seems to me the main line of research he should pursue." 

More and more I had become convinced of the danger of 
opening ravines in hill land, and in 191 3 wrote what represented 
my ideas at the moment : — 

"There is no doubt that an ordinary jungle-covered ravine 
— harmful though it undoubtedly is — is less harmful than a 



RAILWAY CONSTRUCTION AT KUALA LIPIS 219 

well-drained swamp which breeds the mosquito N. willmori 
(A. maculatus). In the opening of an estate many changes 
occur in an undrained ravine, one of which — the filling of the 
ravine with silt from the clearings — is prejudicial to dangerous 
mosquitoes. Whereas the drainage of a ravine by open drainage 
is favourable to the more dangerous mosquitoes. I have no 
doubt that this is the explanation of many severe outbreaks of 
malaria which are reported as following the drainage of such 
ravines. In other words it is the real explanation of what used 
to be explained by ' turning up the soil.' I do not pretend to 
know all about these swamps yet, but it is certainly best to 
leave them alone, neither to drain nor fell the jungle, until sub- 
soil drainage is to be undertaken." 

After my experience of the prevalence and danger of A. 
umbrosus in jungle, both in the coastal plain and coastal hills, 
it is not surprising, perhaps, that I was slow to conceive of the 
possibility of some jungle-covered ravines farther inland being 
free from A. umbrosus, and so free from malaria. Yet this was 
to prove the case ; and although I had realised the advantage 
of leaving a ravine under jungle unless subsoil drained when 
opened, I had not observed the cause for it among the more 
inland hills. 

It was not until 191 5 that Dr Strickland told me he had 
discovered not only a town in the hills which was free from 
malaria, but also the fact that A. umbrosus was not found in 
much of the hill land of the Peninsula; that it was confined 
largely to the coastal plains and coastal hills ; and that in 
the jungle covered ravines of the inland hills it was represented 
only by an occasional umbrosus-like larva. 

Observations in Kuala Lipis and the Pahang Railway Con- 
struction. — These discoveries were of the highest importance ; 
and accompanied by Dr Strickland I crossed the main range 
of hills to where a railway was being made through virgin 
jungle. From Tembeling to Kuala Lipis we searched the 
houses occupied by the construction coolies for adult mosquitoes, 
and examined numerous swamps and ravines for larvae. Where 
the sun was on the stream we often got A. maculatus ; in the 
shade A. aitkeni ; A. barbirostris, sinensis, kochii,, and rossii 
were abundant ; but never an A. umbrosus, either adult or 
larva. 

We then visited the town of Kuala Lipis, which is situated 
on a promontory at the junction of two considerable rivers. 



220 THE INLAND HILLS 

Everywhere it was surrounded by virgin jungle ; its ravines 
were still almost entirely covered by jungle. 

On 7th August 191 5, I made a house-to-house visit in the 
town ; forty children were examined, and only two were found 
with enlarged spleen. One of the two had arrived in Kuala 
Lipis from Ulu Jelei only two days before ; the other was two 
months from Raub — a notoriously malarial spot. 

In the Malay school at Kuala Lipis seven children out 
of seventeen had enlarged spleen ; but enquiry showed only 
two of the children had been born in the town, the others 
having come from Raub (one year before), Kuala Medan 
(two years), Bentong (one year), Bandjar (four years), Pulau 
Tawa (two years). 

In the ravines of Kuala Lipis, only one umbrosus - like 
larva was found. 

Since then, I have often discussed the health of Kuala 
Lipis with people who lived there before the railway came 
to it. They are unanimous not only in witnessing to its 
freedom from malaria, but to its freedom from all mosquitoes. 
So free was it from these pests that people usually slept 
without mosquito nets, which is not done by Europeans else- 
where in this country that I have heard of. 

In travelling along the construction work of the railway, 
we had found the spleen rates were lower the more the place 
was closed in by virgin jungle, and the more permanent the 
class of people examined. 

For example, my notes record : " A summary of all living 
in Tembeling at the time shows that, out of ninety-seven, 
twenty-one had enlarged spleen ; but of the most permanent 
part of the population, viz., those connected with the workshop 
and the children in the kongsis (workmen's houses), most of 
whom had been two years and three months in Tembeling, 
only three out of thirty-six had enlarged spleens, a remarkably 
low rate when we consider that the cleared area of the town 
probably does not exceed ten acres, and that it is entirely 
surrounded by virgin jungle." In contrast to this — 

" Tembeling Estate.- — We found that, among twenty-two 
Tamil adults on Tembeling Estate, eighteen had enlarged 
spleens, and of the eight Tamil children, all had enlarged 
spleens." 

Again, " Krambit, like Tembeling, is shut in by virgin 




Fig. 71.— The River at Kuala Lipis, Pahang. 




Fig. 72.— Coolie Lines for Railway Construction in Pahang Jungle. 
No Anopheles umbrosus found. 

[To face page 220. 



RAILWAY CONSTRUCTION AT BATU ARANG 221 

jungle, except that towards the west a portion of the land is 
covered by lalang, intersected by ravines, shaded by secondary 
growth." Here we found six children, none of whom had 
an enlarged spleen. 

Observations on the Railway Construction at Batu A rang 
in Selangor. — In view of the absence of A. umbrosus from 
the part of the State of Pahang which we had just visited, 
I considered it would be of interest to visit some railway 
construction then being undertaken in the coastal hills of 
Selangor, where I expected to find A. umbrosus. In this 
we were not disappointed, as the following catches of adults 
show ; only a few minutes were spent in each house. 

1 2/9/ 1 5 Station-master's room 

Rest house 

Chinese house 

Clerk's house. 
1 3/9/ r 5 Station-master's house 

Chinese coolie lines, ij miles 
14/9/1 5 5th-mile lines abandoned 

Railway lines at Kundong . 

Wood-cutter's house . 

Railway lines, ii miles from 

Kuang ... 1 

86 5 

Everywhere, in swamps both open and under jungle, we 
found the larvae of A. umbrosus; and as this was hill land, 
the swamps were in the ravines. 

The larvae of A. aitkeni, barbirostris, rossii were also taken. 

Observations in the State of Pahang from the Gap to Ginting 
Simpah via Tras and Bentong. — In order to exclude the chance 
that A. umbrosus had been absent for some unknown reason 
during my previous visit to Pahang with Dr Strickland, I 
again visited it by road. Most of the road is through virgin 
jungle; here and there dotted along it are P.W.D. coolie lines, 
a wood-cutter's house, an occasional shop, and maybe a small 
native holding planted with rubber or fruit trees. 

The larva; of A. aitkeni, maculatus, barbirostris, aconilus, 
and kochii were taken, each in its usual breeding-place. " With 
the exception of the houses in Tras and Bentong, all the 
houses examined for adult anopheles during this three days' 



umbrosus. 


Other A nopheles. 


12 




2 




7 


r maculatus 


4 




26 




12 




2 




18 




2 


4 barbirostris 



22 2 THE INLAND HILLS 

trip were situated in the midst of heavy virgin jungle ; but 
nowhere was A. umbrosus taken, in remarkable contrast to 
my experience in Batu Arang, Batu Tiga, and the flat-land 
estates of Klang." 

Such was Dr Strickland's important discovery. He had 
found a zone of land— the " Inland Hills "which is not malarial 
when under virgin jungle, but becomes intensely malarial 
when the ravines are drained and cleared of jungle. This 
zone is a complete contrast to the " Coastal Plain," which is 
malarial when under virgin jungle, and becomes non-malarial 
when the jungle is felled and the land drained It differs 
too, from the "Coastal Hills," which are malarial, whether the 
land be under jungle or cleared. The differentiation of these 
hill zones was possible from the discovery of the peculiar 
distribution of the mosquito, A. umbrosus. 

I have called it Dr Strickland's discovery, because to him 
more than to any other, our knowledge on this point is due! 
It is true, as will be found in Dr Wellington's interesting 
Chapter (XXVI.), on "The Malaria of Kuala Lumpur," that 
the absence of anopheline larvae from ravines had been 
reported as early as 1907 by Mr Pratt, and confirmed by 
Dr Wellington in 1909. But this had failed to carry convic- 
tion ; partly because the observations had not been published in 
detail ; partly because they were in flat contradiction with what 
was known of apparently similar hill land ; partly because no 
explanation of the contradiction was forthcoming; and mainly 
because no one then suspected the peculiar distribution of 
A. umbrosus. 

It was reported that no anophelines were found in the 
jungle-covered ravine. This was incorrect. For a description 
of the species of mosquitoes that live in the ravines of the 
"Inland Hills" see Chapter XXV. "On Mosquitoes" There 
is no doubt that Messrs Pratt, Fletcher, and Wellington had 
caught more than a glimpse of the truth ; and had there been 
an earlier investigation of the subject it would have been of 
the highest advantage to the Malay Peninsula. 



CHAPTER XXI 

THE MALARIA OF RIVERS 

Rivers differ greatly in different countries; the same river in 
the same country may pass through different zones of land ; 
and in any zone it may alter its character to become narrow 
and swift, or broad, swampy, and sluggish. So in considering 
the malaria of rivers, it may make the subject clearer if I take 
a river at different points of its course and discuss its relation 
to malaria. 

Tidal Rivers. 

Tidal and Brackish Rivers. — This is really the zone of the 
mangrove swamp, and A. Indlowi with which I deal in 
Chapter IX. The river has a muddy bank, fringed with 
mangrove j while behind the mangrove comes the swampy, 
coastal plain. Mosquitoes do not breed in the river bank itself, 
nevertheless, the banks of a river in this land are intensely 
malarial, unless a thorough system of drainage is constructed. 
How unhealthy it can be is seen from the early history of 
Port Swettenham and from the cocoanut estate mentioned in 
Chapter IX ; how healthy it can be made is shown by the 
estates on Carey Island. 

Tidal, Non-brackish Rivers. — With so large a rise and fall 
of the tide (some 16 feet) as occurs in this part of the Straits 
of Malacca, the tidal wave passes fully 20 miles up the rivers 
as they twist and wind through the coastal plain. 

In the upper reaches of the river the water is no longer 
brackish ; and here, as in the lower brackish reaches, no larvae 
are to be found on the river's bank ; but the land through 
which it passes is malarial from A. umbrosus — the inhabitant 
of the coastal plain. In a previous chapter we saw how 
healthy this can be made ; for example, Estates " OO," " TT," 
and"HH." 



224 THE MALARIA OF RIVERS 

Non-Tidal Rivers. 

Rivers with Swampy Banks in the Umbrosus Zone. — Beyond 
the tidal, but non-brackish, portion of the river, we reach a 
part where the character of the land through which the river 
runs is still the important factor in determining the presence 
or absence of malaria. Where the river course is not well 
defined, or the banks are very low, there may be a permanent 
swamp that will be dangerous from the presence of A. umbrosus. 
These swamps may be of great extent ; almost certainly they 
cannot be efficiently drained; to "fill" them with earth would 
cost a King's ransom. The simplest way to make a people 
healthy in such a place is to move them back from the river 
swamp a distance of half a mile or more. The following is an 
example of the problem that may be met. 

Three Estates, " SA," " HW," and " JS," are situated together 
on a Government road. Estates " SA " and " HW " are rather 
above the level of the coastal plain ; they are not dead level, 
yet would not be called undulating land. The drainage is 
good. Estate " JS " is definitely hilly, or rather a hill or island, 
for it is almost everywhere surrounded by lower land ; there 
are no ravines, and no A. maculatus. In 191 5 the health was 
good, the true spleen rate being nil ; the only death in a 
labour force of 114 was that of a child. 

Estate " SA " had been unhealthy, the spleen rate of twenty- 
seven children, examined in January 1916, being 59 per cent. 
The coolie lines were situated about 100 yards or less from 
the road, on the opposite side of which was a piece of flat 
land which Javanese had begun to cultivate, but which until 
a few months before had been under jungle. Thinking it 
probable that the opening of the Javanese land would improve 
the health of Estate " SA," without the estate having to do 
anything, I recommended no action be taken with regard to 
the site of the lines. The fact that the labour force looked so 
much healthier than I expected, from the spleen rate of 59, 
suggested that the improvement had already begun. 

Estate " HW" was also unhealthy. The spleen rate in 
January 1916 was 29 per cent, out of thirty-seven children, 
which was lower than that of Estate " SA." The reason for 
the difference was that whereas the lines on " SA " were close 
to the road and within 5 chains of undrained jungle, the lines 




Fig. 73. 
A River within tidal influence — brackish. 




Fig. 75. 
A Stream too large for Pipe Drainage. 



[To face page 224. 



NON-TIDAL RIVERS 



225 



on "HW" were 20 chains away from the road, and so farther 
from the breeding-place of A. umbrosus. 

When, however, I came to consider how to bring down the 
spleen rate on " HW," the matter was not so simple as on 
"SA," where my recommendation was to do nothing. The 
jungle opposite "SA" had been drained, and was being 
cultivated by the Javanese ; the jungle opposite " HW " was 
undrainable and could not be cultivated, as we found on 
visiting it. 

As the lines were within 20 chains of this swamp, and I 
advise 40 chains as a minimum, it was necessary to inquire if a 
better site could be obtained elsewhere. 

Behind the estate was jungle ; so that the site could not be 
within 40 chains of the back boundary or south of the line 
XY ; there was swamp across the Government road, so the 
site must be at least 40 chains in or south of the line AB. 
The east boundary, being " JS," was harmless, being hill without 
ravine ; the west boundary was " SA," and no dangerous 
anopheles were found in it. So there was the area ABYX 
within which the site might be. A local examination led to 
the selection of a slightly raised portion of the land. In 
May 1916 I made these recommendations in writing; the 
report was sent to the Directors in England, who at once 
cabled their approval, and by September the new lines were 
finished and all the coolies removed, at a cost of $7000. 

On both estates the health improved, as was anticipated. 
On Estate " SA," where the lines remained in the original 
spot, the jungle swamp was removed through the Javanese 
cultivation, the spleen rate was reduced. 

Spleen Rates of Estate SA. 



Date. 


No. Examined. 


Spleen Rates. 


January 1916 
November 1917 


27 
84 


59 
2 



In 1917, of the two children with enlarged spleen, one was 
an old resident ; the other, a recent local recruit. Out of the 
whole labour force of 340 mustered for inspection, there was 
only one case of slight anaemia and one case of fever. The 



226 



THE MALARIA OF RIVERS 



whole force was in splendid health ; and it was apparent that 
the health had begun to improve as soon as the land opposite 
was opened, and before my inspection in January 1916, as I 
had surmised. 




59 in 1916 



A 



S A 

ESTATE 



X 



29 in 1916 



New site 
selected 



H W 

ESTATE 



6 

■5 

o 



B. 



J s \ 

ESTATE 

True Spleen Rate 

™ Nil 



YS 



" [ ""'\us>°"'iji m ^ 



,.»»' 



,,*«■ 



Jungle 



blO. 7^. -I'lan of Estate II W. 



RIVERS STILL FARTHER INLAND 227 

On estate " HW" the coolies had not been so long removed 
from the malarious influence as on estate " SA " ; for it was 
September 1916 before they were removed. But even they 
had improved in health. 

Spleen Rates of Estate "HIV." 



Date. 


No. Examined. 


Spleen Rates. 


January 1916 
November 191 7 
June 1920 
June 1920 


37 
46 

44 
41 


29 

15 

9 

4* 



Rivers Still Farther Inland. 

The Batu Road Swamp. — To decide upon the right method 
of dealing with a river swamp, especially in a large town, is not 
by any means always a simple matter, as this swamp showed. 
It was situated in the centre of the town of Kuala Lumpur, 
the capital town of the F.M.S. It lay between the river and 
a row of houses, the sewage of which discharged into the 
swamp; there were no sewers to convey it to the river. For 
days at a time the swamp was flooded. 

The Sanitary Authority rightly decided to take action to 
abolish this foul swamp ; and issued an order to the owner 
requiring him to " fill " it with earth to such a level that it 
would not be covered by the majority of floods — the filling to 
be to over " average flood level." The engineer for the owner 
estimated this would cost $61,677 (as a matter of fact the level 
given by the Sanitary Authority was incorrect, and the cost 
would have been considerably less, as was discovered afterwards). 
In view of this large expenditure, I was asked to advise on what 
was necessary to prevent the swamp being a nuisance. 

The swamp was not a cause of malaria in my opinion ; and 
Dr Strickland who examined the houses next to the swamp 
confirmed this. He found ''only one child with any enlarge- 
ment at all (of spleen) out of twenty-five." 

Nevertheless, it was a foul spot, which was breeding many 
mosquitoes. 

The level to which I thought the land should be filled was 
about i£ feet above swamp level; and I regarded swamp level 

R 



228 THE MALARIA OF RIVERS 

as fixed by the lowest level at which the sensitive plant, Mimosa 
pudica, would grow. 

Part of the ground was dry, covered by M, pudica, and 
not suggestive of swamp; part was frankly swamp, being 
covered by water ; while other parts were dry at the moment, 
and not covered by M. pudica. 

All around there was a well-defined line at which M. pudica 
stopped growing, and below which the vegetation consisted of 
bulrushes and swamp grasses. 

I regard the mimosa line as the level of the swamp water 
or permanent ground water, because M. pudica cannot grow 
in a swamp. It is a leguminous plant with nitrogenous nodules 
on its roots. These nodules absorb nitrogen from the air, and, 
therefore, must be in what normally is dry soil. 

An engineer with a theodolite took levels at widely different 
parts of the swamp, when I set the staff on the line of the 
M. pudica. The readings (using his own datum) were curiously 
consistent : 

42.51 42-49 42-33 42-12 

The river level was found to be on (10/3/15) 4021. 

My advice was that the whole ground should be filled to 
the level 44, which was fully l\ feet above the mimosa level. 
The cost of filling to the level 44 was estimated by the engineer 
at $2324; a difference of over $59,000 from what was required 
by the Sanitary Authority. 

In view of this evidence the Sanitary Authority obtained 
a report from another engineer, who said : — 

" The level of the line between mimosa and swamp grass 
noted by Messrs Mace, Hall, & Co. as being quite distinct, was 
ascertained in the vicinity of the large patch of low-lying ground 
in the centre of Lot 1 1." 

The reduced levels from town datum were as follows on 
oth May 1915 :— „.,,,, 

' ' Reduced Level 

Reading. Town Datum. 

4 85-90 



86-20 
85-80 
85-20 
85-20 

9 . 85-80 

IO . - . 85-90 

Average . . - 85-70 



RIVERS STILL FARTHER INLAND 229 

It was evident from the readings of the two engineers that 
the mimosa line was something definite, and could be fixed 
with sufficient accuracy to justify action being taken on it. 
The line being fixed, and the cause of the line (the depth 
of dry soil in which the mimosa roots would grow being 
indisputable), the Sanitary Authority adopted my suggestion 
of basing the amount of " filling " on the mimosa line. 

I have discussed this question at some length ; but not 
more than it merits. Riverine swamps occur in many places, 
and in many towns. In Kuala Lumpur there are many acres, 
part belonging to Government, and part to private owners. 
To fill them one foot per acre more than is necessary would 
lead to great waste of money, whether the money be that of 
a private individual or of Government. 

Inland Plains. — It is on the banks of the larger rivers that 
we find the representative in this country of the " Inland 
Plain " ; for it is on too small a scale to furnish examples 
of ancient lake beds or plateaux much above sea-level. Still 
there are some stretches of inland flat land, and they are 
healthy. As an example I may give the spleen rate of an 
estate a few miles beyond Kuala Lumpur, on the river of 
which I have just been writing. The estate, or at least the 
portion of it next to this river, has had a reputation for its 
good health for many years, and the spleen rate justified it. 
On 26th September 1911,1 examined twenty-seven children, 
all of whom were free from enlarged spleen. 

It may be said generally of the larger rivers in this country 
that they are non-malarious ; by which I mean that where the 
banks are well defined, dangerous anopheline larvae will not 
be found in any quantity in the vegetation that may grow 
on the bank. Where the river-bank is not defined, but loses 
itself in a swamp, the health depends on the zone of land in 
which the river is situated ; if in the umbrosus zone, the swamp 
will be dangerous; if farther inland and A. umbrosus is not 
present, it will be harmless ; unless A. aconitus is breeding in it. 
In 1909 I recommended the removal of coolie lines from ravines 
to the banks of another river with entirely satisfactory results. 

The Smaller Rivers. — As one passes still farther towards 
the source of a river, and before the small ravine streams 
are reached, one finds a stream perhaps some 20 feet wide 
and a foot or so deep, pursuing a rather tortuous course down 



230 THE MALARIA OF RIVERS 

an inland valley. The river is clear, the bottom sandy, the 
sides grassy. 

Along the grassy banks are found the larvae of A. maculatus ; 
they are also present in side pools along the river. In heavy 
rain, the stream becomes a raging torrent ; in dry weather, a 
sleepy stream ; but always too big to be put underground in 
subsoil pipes. If malaria exists in such a community, how can 
it be eradicated ? 

Tarentang Estate. — In 191 2 I was asked to advise this 
estate, as malaria had been severe ; and I found there the 
problem described above ; with the complication that many 
small ravines, breeding A. maculatus, ran through the estate 
and discharged into the river. The banks of a clear stream 
are attractive sites for coolie lines, and in many places 
throughout the country have been selected as headquarters 
for a labour force. If such sites could be made healthy, it 
would be an advantage to the whole country to know how it 
could be done. If it were impossible to make them healthy, 
no less valuable to everyone would be the knowledge ; for 
then these sites could be avoided in the future, or abandoned 
if already in use. 

It appeared to me that the procedure to be adopted should 
be experimental ; and, as such, a portion of the cost might 
fairly be borne by Government. Accordingly I suggested an 
experiment both to Government and to the estate ; and both 
agreed to share the expense equally. My idea was to render 
the ravine streams harmless by subsoil drainage, and to oil 
the edges of the main stream. Unfortunately there appears 
to have been a misunderstanding of what I required ; and 
on my next visit to the estate in 1914, I found not only the 
ravines being " piped," but an entirely new channel being 
made for the main stream, at, of course, a much heavier 
expenditure than all the ravine drainage put together. The 
Government labour employed on the drainage had been 
decimated by malaria ; the engineer in charge had been laid 
up so frequently that proper supervision had been impossible ; 
and the work was not satisfactorily carried out. 

A. maculatus still breeds in side pools in the bed of the 
main stream in dry weather, and although the health has 
improved, the unhappy experiment has not been carried far 
enough to warrant any final conclusions. 



THE MOSQUITOES OF STREAM-COURSES 231 

The course of a river has now been traced from the sea 
backwards almost to its source in the hills ; probably in some 
ravine. Of ravines and their malaria I have already written 
in the chapters on Seafield Estate ; so, for the present, shall 
say no more. But before closing I must reprint Dr Strickland's 
unpublished paper on " The Mosquitoes of Stream-courses " 
which sums up the results of his extensive research. 

PAPER S. 



The Mosquitoes of Stream-courses, by Dr Strickland. 

" Of course, at the eye of a stream, exactly where the 
stream-course resolves itself from out the swamp from which 
it springs, it is impossible to say. Sometimes, however, 
especially in the dry weather, the stream commences as a 
series of pools in a definite well-cut course, and such places 
I have included here, although there be no semblance of 
a stream through the pools. 

" I do not include flooded land as being in a stream-course. 
From first to last, the following species have been taken 
by me from stream-course : — 





Per 




Per 




Mille. 




Mille 


Maailatus 


. 340 


Albirostris 


53 


Barbirostris 


• 153 


Umbrostis group 


• 47 


Sinensis . 


. 127 


Fuliginosus 


. 40 


Aitkeni . 


. 67 


Rossii 


. 40 


Karwari . 


. 60 


Leucosfihyrus . 


• '3 


Kochi-tesselatus 


. 60 


Ludlowi . 






" This table shows the very marked predominance of 
maculatus over the other species in this respect, and justifies 
the appellation usually given to it of a stream-breeder, originated 
by Watson. 

" One very common characteristic about a stream-course 
is the absence of grasses at the edge, probably due to the 
scour. That may account for the comparative absence of 
albirostris which otherwise would like the swift current. 

" We will mention a few types of streams and their mosquito 
fauna. 

" 1. Tidal Rivers and Streams. — Along these is usually nipah 
palm and mangrove. The highest spring tides will sometimes 
leave pools of water among the nipah roots and occasionally 
one can find umbrosus in such pools. If the vegetation is 
within reach of the lowest range of tide, nothing can be found. 



232 THE MALARIA OF RIVERS 

It will be noted in the table that ludlowi was never taken from 
a stream-course. 

" 2. Small Streams running sloivfy through Jungle. — At the 
edge among fallen timber may be found species of the 
umbrosus type. 

" 3. Larger Streams running through Jungle, like the Batu 
Pahat river or the Sungei Jembulang. The jungle trees form 
a dense canopy over the edge of the stream, and the current 
is strong and deep enough to keep the edges clear of flotsam 
and jetsam. Consequently, no breeding-places are found. 

"4. Scouring out Pockets in the Banks. — This is the home 
of maculatus and barbirostris, sometimes Juliginosus and aitkeni, 
e.g. Jementah Estate, Johore. 

" 5. Small Ravine Streams under Jungle. — The stream is 
usually difficult to define ; the whole is rather a streaming 
morass. I have recorded aitkeni and species of the umbrosus 
type in such places. 

" 6. Great Streams like the Kelantan river. Such are nearly 
all opened up, unless the hills which come to the edge are 
too steep for Malay kebuns.* In any case, nothing can be 
found along the banks except in the interesting case of a 
terrace of the river-bank, showing a seepage swamp. In 
such a place at Kota Bharu, Kelantan, I obtained kochi. 

" 7. Mountain Torrents. — It may be taken that no mosquito 
lives actually in the torrent, but only in pools along the course, 
or in silted-up pools. I have there taken leucosphyrus and 
rossii, while in pools among granite boulders I have obtained 
maculatus, leucosphyrus, aitkeni, or if the jungle covers such 
places only aitkeni. 

" 8. Certain Streams tributary to great streams like the 
Kelantan or Pahang, which have reached the base level of 
erosion, and that a muddy base, have umbrosus species growing 
in them, if under jungle, or kochi and maculatus if exposed." 

* Small estates, or gardens, or native holdings. 




Fig. 76A. 




Fig. -6b.— The Perak River. 



[ To face page 232. 



CHAPTER XXII 

THE REAPPEARANCE OF MALARIA 

DURING the past twenty years malaria has reappeared in 
greater or less virulence in several places from which I had 
seen it disappear. As the causes which led to the disappear- 
ance of the disease had been observed, it was possible to 
study the changes which brought about its reappearance ; 
and by appropriate action to make the places healthy again. 
Probably an experience of true alterations of health and 
sickness is comparatively rare ; in any case they are of 
interest and value to the sanitation, so I will record them 
in some detail. 

I. 

The Reappearance of Malaria at Port Swettenham. 

[1909]. — When, in 1901, the Port was opened, in order to 
obtain exact information of the number of people who were 
attacked, I caused, as already mentioned, a daily visit to be 
made to each Government house. This was continued for 
several years. When it was discontinued, I caused the Deputy 
Health Officer to inform me when any officer complained of 
fever, and no officer received sick leave until he had come to 
Klang, and his blood had been examined. Further, I issued 
instructions to the Deputy Health Officer, who was also in 
charge of the Dispensary, that no person living in Government 
quarters was to be supplied with quinine except on my orders. 
I had thus a very firm grasp on the Government population at 
Port Swettenham. Seeing those who, complaining of sickness, 
sought sick leave, and making blood examinations if there was 
any complaint of temperature, I am in a position to state that 
no officer suffered from malaria from 12th July 1904 until 
December 1906. In that month three officers were found to 



234 



THE REAPPEARANCE OF MALARIA 



have malaria, which had evidently been contracted in the 
Port. 

The matter was at once reported to the Chairman of 
the Sanitary Board, the late Mr J. Scott Mason, afterwards 
Governor of British North Borneo, and, accompanied by the 
Executive Engineer, we made a careful survey of the drainage 
conditions of the Port. 

It was, I think, more than a coincidence that, at the very 
moment of the recrudescence, cement inverts had been put into 
the road drains at such a level that they effectually blocked 
all the lateral drains which previously opened into them. The 
whole of the area marked " C " on the plan (Fig. 9) was, 
therefore, much less efficiently drained than previously ; in fact 
was now entirely without any drainage, as the photo shows. 

We recognised the fact that a larger population than 
formerly were living entirely outside the bunded area. In 
1904 it numbered 548, whereas in 1901 only 127 lived beyond 
the bunds, and those were housed along the Klang Road on 
the edge of a deep drain, and on land fairly well drained before 
the new concrete inverts had been put in. 

The spleen rate was affected by the outbreak, as the following 
table shows : — 



Year. 


1904. 


1905. 


19015. 


1907. 


1909. 


Blood examination — 
Number examined 
Number with parasites 
Per cent, with parasites 

Spleen examination — 
Number examined 
Number with enlargement . 
Per cent, with enlargement . 


87 

1 

1. 14 


76 




IOO 
5 

5 

IOO 
2 
2 


41 

9 

21.9 


I09 

9 
8.9 



In 1906, 1 found evidence in the children of the recrudescence 
of the disease, simultaneous with its reappearance among the 
adults, as I shall relate. In 1907, the examinations were made 
by a dresser. In 1909, I myself made them, and visited, along 
with the present Medical Officer of Klang, Dr Millard, every 
house up to the 4th mile on the Klang Road. Practically every 
child in the town was seen and was examined by both of us. 

We also recognised that the drainage system within the 
bunds was not so efficient as previously, since in some places 




One of the lateral Drains in Area " C " at Port Swettenham, blocked by a new cement 
drain in 1906. It was swarming with Anopheles. 




Fig. 78. 
Another of the blocked lateral Drains in Area 



1 at Port Swettenham in 1906. 

[To face page 234. 



CRITICISM OF ORIGINAL DRAINAGE SCHEME 235 

filling had sunk, and in other places drains have been diverted 
and lateral drains obstructed by cementing the mains. The 
Boatrd decided to spend the balance of a vote in 1907 in cutting 
outlets for area " C," but owing to the great competition for 
labour at the time, it was absolutely impossible to do so. In 
1907, I formally brought these matters to the knowledge of 
Government. 

In 1908, when I was in England on leave, the condition 
was still further aggravated by the extension of the railway 
embankment from the point marked " K" to the point marked 
" H," in order to provide further wharf accommodation. This, 
of course, completely blocked the outlet of the whole of the 
drainage from the South bund. I am informed that malaria 
increased rapidly then, but an outlet was soon made for the 
water beyond the end of the railway ; and as the figures 
show, the amount of malaria now (1909) in Port Swettenham 
is not very serious. Government, however, appointed a 
Commission to make recommendations in 1908 ; and a sum 
of $27,000 is being spent in improving the automatic outlet 
valves, improving and increasing the bunds, and in improving 
an open sewer system for many of the houses. 

I am of the opinion, however, that malaria will not entirely 
disappear from Port Swettenham until it is recognised that a 
large proportion is now outside the protected area. The 
bunded area should be increased to include these. 

[1909] — Criticism of the Original Drainage Scheme at Port 
Swettenham. — In 1901, our chief fear was that mosquitoes 
would breed in the drains within the bunds. We considered it 
essential the drains should have such a fall that they would dry 
during every tide, or at least would have such a current as 
was calculated would prevent the insect from breeding within 
them. Accordingly, the level of the outlets made in 1901 
was that of about half tide. At such a high outfall level, 
and with a grade to provide a good current, in many places 
the drains soon ran out practically on to the surface of the 
soil, especially at the top of the system. Places where water 
stood when the drains had been completed were, therefore, 
" filled in " at great expense. Since then, filling has been con- 
tinued to provide sites for buildings, etc. It must be clearly 
understood that expense was not allowed to stand in the way 
of success, as the whole existence of the Port was at stake. 



236 



THE REAPPEARANCE OF MALARIA 



Experience has shown that our fears were groundless ; and 
that the danger from open drains in flat land is nil, if they are 
kept moderately free from weeds. Any further works will, 
therefore, be immensely cheaper, since the outlets of the new 
drains can be put at the level of low water neap tides. 
Deepefting of the drains is more satisfactory than filling, as the 
cost is a mere fraction ; this cannot be too strongly insisted tipon. 

I am indebted to Government for the figures below and the 
levels, which show that the general level of Port Swettenham 
is 2 to 3 feet below that of spring tides. 

The levels on the plan range from 50-24 to 54-26, and the 
highest known tide was 56-36, and the following are the official 
levels : — 

H.M.S. "Waterwitch" Bench Mark. 

The surface is 14 feet 4 inches above the datum used for the 
reduction of sounding's. 



Low-water spring tide 
B.M. above datum 
High-water spring tide 
Low-water „ 

High-water ordinary tide 
Low-water „ 

High-water neap tide 
Low- water ,, 

High- water on 30/10/09 
Invert of culvert 87 . 

Invert of flap valves in South bund 

Invert of flap valve in North bund 

* Highest known tide 



39-13 

'4-33 

55-36 

39-13 

51-37 

42-35 

4665 

45-46 

56-36* 

48-60 



48-54 
48-86 



/47-S9, 

(46-67 



I make these criticisms in order that others may benefit by 
the mistakes made in our pioneer work. 

The level of the outlet is most important ; and when a sea 
is tidal, bunding gives enormous powers of drainage. I need 
only mention how the English Fens have been drained by 
bunding, and incidentally malaria has disappeared. I think 
that is more than a coincidence. 

[1920] — Port Swettenham from 1 909 to 1920. — In 1909, 1 was 
unable to induce the Government to extend the bunded area to 
include Area " C," and so to protect the large population living 
outside the area originally protected. But Mr Byrne, the 
District Engineer of Klang, appreciated my suggestion of 




Fig. 79.— Culvekt at Port Swettenham. 

The photograph shows the old culvert on the left. The small culvert on the 
right is the low-level culvert put in by Mr Byrne. It is three feet lower than the 
old culvert, and has enormously improved the drainage of the town. The high 
tide of October 1909 came over the railway at this point. 



[To face page 230. 



PORT SWETTENHAM FROM 1909 TO 1920 237 

lowering the drainage level ; and he put a small low-level 
culvert beside Culvert No. 87, only 3 feet lower. This improved 
the drainage of the land so much that, when a scheme for the 
whole of the Port came to be discussed in 1914, I insisted on 
a low-level scheme being put down ; and pointed out that the 
level of the outlets might go still farther down that of the 
small culvert at No. 87. This was done in the new scheme, to 
be presently described. 

In 191 1 the decision to build a quarantine station at Port 
Swettenham for coolies arriving from India, once more made 
the malaria a question of importance and urgency. To pour 
thousands of coolies into a quarantine station where they 
would contract malaria would have been a disastrous course 
to pursue ; and I advised the Planters' Association of Malaya 
to insist on the Port being made healthy as a condition of 
a quarantine station being built there. This they did ; and 
the work was begun. The area required for the building was 
bunded and drained (being below high-tide level this was 
necessary before even a start could be made with the buildings) ; 
but on Area " C," which was adjacent to the station, the work 
was not completed for several years after the scheme was 
sanctioned. The bund was built and a gate of sorts erected ; 
but the tide entered almost unimpeded ; no drainage system 
existed ; and the last condition, which was worse than the first, 
lasted until 1917. 

In 1914 a plan for the drainage of the new area, excluding 
that actually occupied by the quarantine station, was prepared. 
But it included many of the mistakes which one would expect 
from an engineer who was not familiar with the previous 
history of the drainage of the Port. Over $ 100,000 was to 
be spent on masonry or glazed earthenware drains, most of 
which would have been quite unnecessary. But the chief 
fault lay in the omission to consider the level of the outlets of 
the drains through the bunds. The total estimate was $149,342. 

The plan was rejected ; and a small committee appointed 
to prepare another. I pointed out the history of the drainage 
of the Port, the advantages of a low-level drainage system ; 
and insisted that masonry drains should only be laid down 
where sewage had to be carried in addition to the ground 
water ; where the latter only was present, open earth drains 
had proved to be sufficient on estates in similar land. On 



238 



THE REAPPEARANCE OF MALARIA 



these lines a new plan was prepared, the estimate for which 
was $68,849, a saving of over $60,000 on the first scheme. 
From a malarial point of view the new plan was infinitely 
superior ; another illustration of the connection between know- 
ledge, efficiency, and economy. In view of the importance 
of the matter I give a summary of the two estimates ; so 
that they may be compared and the lesson more clearly 
brought out. 

Estimate of First Scheme. 

Earth drains ..... $2,677 

Masonry drains, 9-inch . . 22,936 

12-inch .... 75, 6 3 6 

Earth drains with glazed inverts . . . 8,657 

Culverts ...... 16,860 

Screw-down gates, 9 9,000 



Contingencies, 10 per cent. . 
Total 

Estimate of Second Scheme. 

Earthwork in drains 

Masonry work in drains and culverts 

Subsoil drains 

New bund at outlet " C " . 

Filling low ground, say 

Strengthening bund 

New sluices, including railway culvert at "B" 

Contingencies, 10 per cent. . 
Total 



ii35>766 
'3,576 

$149,342 



$13,200 
14,000 

3,3°° 

360 

3,000 

2,500 

26,230 

$62,590 

6,259 

$68,849 



This estimate and plan were approved, and the work will 
be completed in the course of 1920. Already it is shown how 
advantageous deep-level drainage is; all the portions already 
drained have a great depth of dry soil. 

The Engineer-in-charge, Mr F. D. Evans, has supplied me 
with the following data of the levels : — 

Mean sea-level is given as 100. 

Maximum spring tides range between about level 92-00 

and level 108-00. 
Minimum neap tides range between about level 98-6 and 

101-3. 
The highest tide on record is about 109- 5. 



PORT SWETTENHAM FROM 1909 TO 1920 239 

The sill of outlet "A" is set lower than the level 95, as an 
experiment; but the drains were not set down to it. Outlet 
"E" with its drains is set lower than 96. The outlets in creeks 

Counter Weight 



I If ; 



Land 
End 



. 



• ' t i 1 - 



^0=11? 



«^z 



Draw Gate 



Section through Sluice 

Fig. 80.— Section through New Sluice Gate at Port Swettenham. 



Flap Gate 



are set higher. The engineer is satisfied with the lowest outlet; 
and adds that all the drains could be down to 95, or 5 feet 
below mean sea-level. 

Only on one or two days in the month are the gates kept 



240 THE REAPPEARANCE OF MALARIA 

closed on account of the neap tides ; this has not proved 
a serious disadvantage, as the gates, which in addition to 
automatic flaps have screw-down valves, keep the water out 
effectively. The great depth and capacity of the drains, as 
well as the large capacity of the well-drained soil to absorb 
rain, prevent flooding of the land when heavy rain falls during 
the period when the gates are shut. 

The population of Port Swettenham in 1920 was found from 
the Rice Controller's forms to be approximately 6000. 

The spleen rate of the Malay school children was 7 per 
cent. ; but the true rate was nil. At the examination in 1920 
there were forty-two children present. Of these, three had 
enlarged spleens ; two were brothers who had come two years 
before from Port Dickson, and one, a policeman's child, had 
come from Rawang. All three gave a history of fever before 
coming to Port Swettenham. 

II. 

The Reappearance of Malaria on an Estate within 
Tidal Influence. 

A few miles from Port Swettenham, there is an Estate "CC" 
situated on a tidal river, the water of which is practically pure 
sea water. Most of the estate is above the reach of high tides, 
but portions are within tidal influence ; and so the estate at 
these portions is enclosed within embankments. The drainage 
was good ; the land well cultivated ; and there was a large 
healthy labour force as free from malaria as any flat-land 
estate in the district. The death rates were low, 9, 5, and 
9 per mille in 190S, 1909, and 1910 respectively; and the 
spleen rate only 3 per cent, in eighty-two children in 1909; 
the daily number in hospital out of a labour force of several 
hundreds, usually between two and four ; and the trivial ill- 
nesses treated on the estate hardly more. 

There were a few more cases of malaria than usual towards 
the end of 1910; but suddenly in September 191 1 malaria 
became virulent. The death rate jumped from 9 in 1910 to 
101 in 191 1 ; the spleen rate rose from 3 in 1909 to 58 in 
191 1. The hospital could not contain the sick; and in 
November there was an average of eighty sick on the estate 
in addition to over thirty daily in the hospital. 



THE CAUSE OF THE OUTBREAK 241 

The outbreak caused great loss to the estate. Some $5000 
were spent on the hospital in new buildings, but that was the 
least of the loss. The Indian labour force rapidly melted 
away from about 600 to 300 coolies ; the rubber crop could 
not be collected, and was short of the estimate by 30,000 lb., 
which at the then price of rubber probably represented a loss 
of some £6000 sterling. 

The Cause of the Outbreak. — The year 191 1 was more than 
usually malarious, and a breakdown in the quarantine arrange- 
ments at Penang had a serious effect on the mortality of the 
year. But the estate had recruited only eighty-four new coolies, 
and something more than an annual variation seemed necessary 
to account for the outbreak, which showed itself not merely 
in attacks on the adults, but also in its effects on the children, 
many of whom died suddenly. 

For a time I was completely at a loss to account for the 
epidemic. In ten years I had never seen the reappearance 
of malaria on a flat land estate ; none of the lines, as far as 
I knew, and I thought I knew the estate thoroughly, were 
within 40 chains of jungle or swamp ; and the manager assured 
me this was so. I was, therefore, seriously alarmed at the 
outbreak ; it looked as if we could not rely on healthy flat 
land estates remaining healthy ; that malaria, on the flat land 
estates, might become persistent, as in hill land, from the 
appearance of some malaria-carrying anopheles hitherto not 
recognised. For the whole rubber industry, indeed for the 
whole country, the outbreak looked most ominous. 

Accordingly, I searched every drain, pool, and puddle close 
to the coolie lines, and among the rubber trees for some 
new anopheles ; but without discovering any. 

In the course of my examination, I decided to tour the 
whole estate, and then I discovered the cause of the outbreak 
was a very simple one. 

Requiring increased line accommodation for his labour 
force, in May 19 10 the manager built new lines about 20 
chains from the jungle, without realising that the jungle was 
so near, for at two points the boundary of the estate bends 
inwards, instead of running in a straight line as I had 
assumed it did. The new sites were responsible for the cases 
of malaria in 1910, which had quickly disappeared; and it 
was not until September 191 1 that the disease became of 



242 



THE REAPPEARANCE OF MALARIA 



serious consequence — that is some fourteen months after the 
lines had been built. 

The outbreak would have been confined to the new lines, 
but, for estate reasons, the labour force had been redistributed ; 
many of the infected coolies had been moved back to the 
old lines, and the healthy coolies moved to the new lines. 
In consequence of these changes, when I came to investigate 
the outbreak, I found malaria cases in the old lines, and the 
disease appeared to be spread over the whole estate. It was 
only after I discovered that the new lines were close to 
the jungle, and made inquiry about any changes in the 
distribution of the labour force, that the whole story was 
elucidated. 

The Remedy was obvious. The new lines were at once 
abandoned ; others were built on the old site, and the health 
at once improved, as the following figures show : — 



Year. 


Labour Force. 


Death Rate. 


1907 


430 


30 


1908 


432 


9 


1909 


394 


5 


1910 


516 


9 


1911 


445 


IOI 


1912 


354 


19 


1913 


461 


15 


1914 


450 


20 


1915 


357 


11 


1916 


325 


27 


1917 


356 


8 



Spleen Rates. 



Date. 


Number of Children 
Examined. 


Spleen Rates. 


igog December 
igii October 
igi3 January 
igi4 March . 
191S March . 


82 
86 

73 
112 
104 


3 
5S 
19 

4 
0.9 



In 1918 the only child with enlarged spleen came from 
a malarious estate in Johore. The moral is plain. An Estate 
Medical Officer should know by inspection the whole of an 
estate, and should, if possible, possess a plan of it. 



THE STORY OF A COAST RAILWAY 243 

III. 
The Story of a Coast Railway. 

In Chapter V. I told the story of a coast road ; how the 
road blocked the drainage of land inland to it ; how it 
appeared to be responsible for a great wave of malaria ; and 
how, as drainage was improved, the malaria gradually dis- 
appeared over a wide extent of country. Many years later, 
history was to repeat itself in the same area ; this time 
the offender was a railway running parallel to the coast. 
Fortunately, the outbreak was less severe on the whole, 
although intense enough in places as I shall show. It is of 
interest, too, that the outbreak did not occur until some 
considerable time after the construction had been completed ; 
it was not due to the construction coolies and camps to which 
Major Christophers and Dr Bentley have so clearly traced 
many outbreaks in India. 

The railway, like the road, runs from Klang to Kuala 
Selangor, a distance of some 28 miles; for the first 12 miles 
it is on the sea side of the road, but at that point it crosses 
the road and runs along rubber estates and through native 
holdings. From the 12th to the 15th mile, it is within a mile 
or so of the sea ; and the land in this section, being close to 
the mangrove zone, is at a rather lower level than along most 
of the track. It was here the malaria first showed itself. 
The railway was opened to traffic in 1914. 

Malaria reappears on " PG " Estate. — For a year or so 
after it was opened in 1906, this estate suffered from malaria; 
but by 1907 it was healthy, and remained so until 1915, as 
the death rates show. In January 191 3, the spleen rate of 
120 children was 4 per cent. 

The health continued satisfactory until September 191 5; 
towards the end of that month, and until the end of the year, 
malaria was present to a considerable extent. In view of the 
complete freedom from malaria in the past, it seemed at 
the time impossible to believe the whole of the ill-health 
was due to malaria; especially as only 3 out of 120 children 
had enlarged spleen. Accordingly, 150 coolies, who were 
anaemic, were given a course of chenopodium treatment in 
order to eliminate ankylostomiasis as a contributing factor in 

s 



244 THE REAPPEARANCE OF MALARIA 

the ill-health (about 99 per cent, of Indian labourers harbour 
the worm). 

Health improved somewhat in the early months of 1916, 
these being the least malarious months in the year ; but, by 
July, there was no doubt we had to face the fact that, for 
some reason or other, malaria had taken a firm hold on the 
estate. Not only had the acting manager suffered from the 
disease, but so had his servants. Of seventy-two coolies who 
had arrived from India between 1st November 191 5 and 
31st July 1916, sixteen had absconded; and of the remaining 
fifty-four, no fewer than thirty-nine, or 72 per cent., had suffered 
from malaria since their arrival on the estate. Finally, the 
spleen rate had jumped from 3/120 (2-5 per cent.) in September 
1915 to 35/144 (24-3 per cent.) in July 1916. 

The Cause of the Outbreak was difficult to explain. The 
lines remained on the sites they had occupied for years ; the 
drainage of the estate had been improved year by year. 
It was therefore necessary to look outside the estate boundary 
for the cause; some condition that had come into force within 
the previous two or three years ; something that had presumably 
created mosquito breeding-places, which had not previously 
existed. 

Having this in mind, it occurred to me that, although 
the railway had not interfered with the estate drainage, it 
might have done so with that of the native holdings ; and, 
in any case, had probably created a series of borrow pits 
which would be breeding-places for anopheles. An examina- 
tion showed this to be the case. 

In borrow pits along the railway, the following species of 
anopheles were found: A. rossii, A. sinensis, A. umbrosus, and 
in enormous numbers A. ludlowi. A. umbrosus was a known 
carrier. Dr Barbour, who kindly dissected some A. ludlowi, 
found in the first he examined the salivary glands "stuffed 
with sporozoits " (13/8/16). 

An interview with the Acting General Manager of Railways 
found him willing to drain the borrow pits ; a cable from the 
directors of the estate gave the manager a free hand to 
carry out my recommendations. The borrow pits and native 
holdings had their drains opened up ; oil was freely used 
and health rapidly improved. To-day the health is excellent 



THE CAUSE OF THE OUTBREAK 

Death Rates. 



245 



Year. 


Labour Force. 


Death Kate per 1000. 


1907 


200 


IO 


1908 


278 


14 


1909 


224 


8 


19IO 


301 


9 


igil 


43° 


30* 


1912 


502 


3 


1913 


472 


10 


1914 


542 


12 


1915 


605 


36 


1916 


472 


42 


1917 


462 


3° 


1918 


453 


57t 


1919 


452 


13 



1 Quarantine. 



t Influenza. 



The spleen rates show a similar rise, and are now coming 
back to normal. 



Year. 


No. Examined. 


Spleen Rates. 


1913 January 

1 91 5 September . 

1916 July . 

1917 September . 

1918 March 

1919 November . 


120 

120 
I44 
I30 

95 
132 


4 

2 

24 
28 

13 

8 



In 1919, at the examination, ten of the eleven children 
with enlarged spleen had been several years on the estate ; 
so it is evident the enlarged spleens are evidence of the 
outbreak of 191 6. 

In a letter dated November 1919, the manager tells me, 
" At the present time conditions of health could not very 
well be better." 

Estate A.— The adjoining estate suffered in a similar way ; 
and so did others to a less degree. The cure was similar. 
It is unnecessary to give these in details. 

The wave of malaria spread inland to a considerable 
distance and affected estates which one expected might have 
escaped. A number of conditions exist in this district, which 
call for careful investigation in the light of our present 
knowledge of malaria; for this outbreak shows the margin 
of safety of some of these estates is small. 



246 THE REAPPEARANCE OF MALARIA 

Before closing this section I would appeal to the engineers 
of this and other countries, not to allow history to keep on 
repeating itself. Some time ago I was reading a book about 
the Fens of Lincolnshire in England, and therein noted some 
things not without bearing on this matter. "The Romans, 
discovering the remarkable fertility of certain of the dry or 
drying parts, desired to increase their area, and formed a 
rude plan for the reclamation by embanking. ..." " They 
laid down, too, certain causeways across the Fens, a notable 
example of which extends from Denver in Norfolk, over the 
Wash to Chark, and from thence to Marsh and Peterborough, 
a distance of about 30 miles. The Roman embankments, 
however, along the coast seem to have had the result of 
increasing the inundation of the low-lying lands of the Level." 
Then came some lines, as a quotation, the source of which is 
not given — "whilst they dammed the salt water out, they 
also held back the fresh, no provision having been made for 
improving and deepening the outfalls of the rivers flowing 
through the Level into the Wash. The Fenlands in winter 
were thus not only flooded by the rainfall of the Fens them- 
selves, and by the upland waters which flowed from the 
interior, and also by the daily flux of the tides which drove 
in from the German Ocean, holding back the fresh waters, 
and even mixing with them far inland." 

So there is precedent for coast roads, if not for coast railways, 
interfering with drainage; but surely work which "leaves a 
trail of malaria behind is bad engineering." It is high time 
to break with the past. 



IV. 

Malaria from the Delayed Spread of 
a. maculatus. 

Klang Tow?i. — The town of Klang is situated at the end 
of a small range of low hills isolated from other hills belonging 
to the group of coastal hills. The malaria from which it 
suffered originally was carried by A. umbrosus ; and simple 
open drainage eliminated the mosquito and its malaria. Being 
isolated from the other hills, which from 1901 to 1907 were 
still under jungle, the town for long escaped invasion by A. 




Fig. 8i.— Wicken Fen. 
The most interesting relic of the true Fen. " Here we find the peace of the fens 
unbroken . . . where the reeds grow beautiful along the watersides, guarding from sight 
the last home of rare and beautiful things, which almost everywhere else have been 
destroyed by man." — Camb. Geog. 



.fSfflfc, 




Fig. 82. — WlNGLAND Marsh, near Sutton Bridge, in Lincolnshire. 

Reclaimed from the sea, and under cultivation. (" Marsh," in Lincolnshire, 

means salt-water swamp ; " Fen," a fresh-water swamp.) 

[To face page 246. 



KLANG TOWN 247 

maculatus. But with the great opening of land from 1907, 
due to the growth of the rubber industry, the adjacent hill 
land was gradually cleared of its jungle ; A. maculatus became 



PLAN No.i OF KLANG 

Key Plan showing general extension into New Town area 

Disposition of Drainage Blocks 

from plan by Mr. Byrne 



Scale. Half Mile 




Emery Walkci I.Ul. sc. 



FlG. 83. — Plan of Extension of Drainage of Klang Town. 

widespread in the hills; and in 1913 this mosquito was 
found in small quantity in some of the hill-foot drains in 
Klang town. Occasional cases of malaria occurred ; but the 



248 



THE REAPPEARANCE OF MALARIA 



disease never gained a serious hold on the town ; for soon 
after the discovery of the insect, the open hill-foot drains 
in which it had been found were converted into subsoil 
drains. 

The town had increased in size ; to-day (1920) the population 
is over 20,000. To protect them a scheme for improving the 
drainage of what may be called the " suburbs " was prepared 
by Mr Harold E. Byrne in 1916, at an estimated cost of 
$78,400. It drains an area of 1868 acres. The scheme was 
approved, and has since been carried out except for some of 
the sluice gates. 

Although occasional cases of malaria occur in Klang, 
particularly from the less well-drained land between the 
railway and the river, the total amount is small, as the spleen 
rates show. 



Spleen Rates of the Anglo-Chinese 


School. 


Date. 


Number of 
Children Examined. 


Number with 
Enlarged Spleen. 


Observer. 


1 91 5 December 

1916 „ 

1917 
1918 

1919 

1920 June . 


125 

151 
172 

163 
198 

135 


■ { 

I 
2 
I 
I 
2 


Chief Dresser, 

Government Hospital. 

n 11 

11 11 

11 11 
M. Watson. 



This school has pupils of all nationalities, Chinese, Tamils, 
Malays, etc., and is representative of the general population. 
On 8/6/20 I examined the children only under fourteen 
years of age. Of the two with enlarged spleen, one had 
arrived only three months before from an estate where he had 
suffered from fever ; the other was eighteen months from 
India where he had fever. 



Spleen Rates of Malay Schools. 



Name of School. 


Date. 


Number of 
Children Examined. 


Number with 
Enlarged Spleen. 


Bukit Rajah School 

11 n 
Klang School 


1917 December . 
1920 March 
1920 ,, 


75 

93 

130 


3 
3 
5 



BATU UNJOR ESTATE 



249 



Of the five children with the enlarged spleen in Klang 
Malay School in 1920 — only one lived within town limits. 
All these figures show that Klang still retains a fairly 
complete immunity from malaria. 

Batu Unjor Estate. — About a mile from Klang on the Langat 
Road is what is now called Batu Unjor Estate ; and on the 
opposite side of the road, Tremelbye Estate and some native 
holdings. At the time this part of Tremelbye was under 
jungle, it was full of A. umbrosus, as I recorded at page 14 ; 
and the bungalow of Batu Unjor Estate was malarious. 

With the opening of Tremelbye Estate in 1906, A. umbrosus 
and the malaria disappeared ; and Batu Unjor became a healthy 
estate, described as Estate " X " in the earlier part of this 
volume. 

It continued healthy until 1913, when a ravine in a native 
holding opposite the lines of Division I. was invaded by A- 
maculatus. The native owner at first refused to permit the 
estate to control the mosquitoes, and a sharp outbreak of malaria 
occurred, showing the maculatus rise in the month of May. 



Admissions to Hospital for Malaria. 
1913 for the Whole Estate. 191S for First Division only. 



1U13. 


A'lmisxions. 


WIS. 


Admissions. 


January 

February 

March 

April . 

May . 

June 

July . 

August 

September 

October 

November 

December 




10 

2 
IS 
22 

60 
36 
9 
20 
30 
26 
40 
21 


January 

February . 

March 

April 

May . 

[une . 

July . . . 

August 

September 

October 

November 

December . 


2 

I 

17 

18 

25 
13 
12 

15 

4 
1 




Dr Ansley- Young gives me the spleen rates taken quarterly 
since 1915. The contrast between Division I. which is close 
to the hill, and Division II. which is out on the flat land, is 
striking. Dr Ansley-Young attributes the rise of malaria in 
1918 to some breeding-places having been overlooked by the 
oilers ; in fact he found A. maculatus breeding close to the 
lines. 



250 



THE REAPPEARANCE OF MALARIA 



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HARON AND KLANG LANDS ESTATES 251 

Estate " S." — Haron and Klang Lands Estates are, like 
Klang town and Estate " X," situated on a small range of 
hills. They lie about 3 miles from the Klang range, and parallel 
to it. Most of the range was, until comparatively recently, 
covered by jungle, and the malaria was caused by A. uvibrosus, 
which was abundantly found in the jungle, coolie lines, and 
bungalows. 

In 191 2, on my recommendation, close on 200 acres of jungle 
were opened up, in two places — which pushed the jungle, if not 
40 chains from the lines, at least much farther than it had been. 

In view of the extension of A. maculatus to Klang and 
Estate "X" in 1913, I was anxious lest a similar event should 
occur on the hill division of this estate. Klang Lands Division 
is flat land, and the spleen rate at once fell ; the hill division, 
Haron, contains only one ravine, which I searched time and 
again for A. maculatus without success. 

The following figures show the death rates and spleen rates. 

Death Hates per 1000. 



Year. 


Labour Force. 


Death Rate. 


1908 


262 


116 


1909 


373 


16 


1910 


573 


54 


1911 


768 


97 


1912 


1061 


10 


1913 


1065 


26 


1914 


499 


30 


1915 


35i 


H 


1916 


432 


16 


1917 


506 


26 


1918 


499 


47 


1919 


477 


20 



Spleeti Rates. 



Year. 


Haron. 


Klang Lands. 


Number of 
Children Examined. 


Spleen Rates. 


Number of 
Children Examined. 


Spleen Rates. 


1909 
1913 
1915 
1916 

1917 
1920 


32 
84 

27 

53 
70 
36 


31 
15 
22 
16 
14 
36 


20 
51 
25 
33 
37 
46 


20 
7 

4 
3 


4 



9K2 



THE REAPPEARANCE OF MALARIA 



The position, therefore, was that while the health as a 
whole had greatly improved, and the flat land division had 
become practically free from malaria, on the hill division the 
spleen rate refused to fall satisfactorily, and malaria still 





Jan. 

Feb. 

Mar. 

Apr. 

May 

June 

July 

Aug. 

Sept. 

Oct. 

Nov. 

Dec. 


16 
15 




























14 


h 


[AR 


ON 


ESTAT 


E / 


























13 






19 


19 




















12 




























11 




























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Th 


e M 


acul 


atus 


W, 


ive 














1 










o 


f M 


alari 


a 










































Fig. 84. — Chart of Maculatus Wave in 1919. 

persisted. It is true jungle swamp existed within 40 chains 
of the lines, but I was not completely satisfied that it was 
responsible for all the malaria. 

In 1919 I was on leave ; and on my return found there 
had been an outbreak of malaria in the middle months of 



HARON ESTATE 



253 



the year on the hill division with the characteristic curve of 
A. maatlatus malaria. No larvae were, however, found in the 
ravine in February and March of 1920. But an examination 
of the children showed the spleen rate was higher than it 
had ever been : the rate for fourteen children in the lines 
nearest to the ravine was no less than 57 per cent. ; against 
22 per cent, for seventeen children in lines farther off. 

I felt pretty certain after this that A. maculatus had been 
in the ravine in 1919, and would probably return in 1920, 
on the cessation of the wet weather. Since the cost of oiling 
would be considerable, it appeared to me more satisfactory 
to prove definitely the existence of the mosquito before 
recommending oiling. Towards the end of May malaria began 
to increase, and A. maculatus was found in the ravine in great 
abundance. Oiling was begun at once, and I have little doubt 
will give excellent results ; for the manager, Mr Hammond 
Smith, has had experience of, and success with, oiling on 
Pitchakawa, an estate situated at the other end of this same 
small range. 

Some years ago I found A. maculatus in the ravines of 
Pitchakawa, and oiling was begun. The spleen rates show 
the results. 

Spleen Rates. 



Year. 


Number of 
Children Examined. 


Number with 
Enlarged Spleen. 


Spleen Rates. 


1914 
1916 
1917 
1920 


41 
46 
28 
45 


18 
26 

13 
6 


43 
56 
46 
13 



In 1920 all the six children with enlarged spleen had been 
over five years on the estate, except one who had been 
three years. 

Of twenty -seven children transferred from Klang Lands 
Divisions about eight months ago, not one had an enlarged 
spleen. All the children looked well and healthy. Excellent 
work had been done here. 



254 



REAPPEARANCE OF MALARIA 



V. 
The Reappearance of Malaria on a Hilly Estate. 

The estate, which comprises both hill and flat land, has 
its coolie lines at the foot of the hills, because there is not 
sufficient flat land to allow the lines to be built half a mile 
away from the hills. 

As a consequence of the presence of A. maculatus, the 
estate was intensely malarious. Between 1907 and 1910 no 
fewer than eight Europeans resigned on account of ill-health, 
one of them died. The coolies suffered equally. In 191 2 
a subsoil drainage scheme was carried out very thoroughly 
by one of the staff of the estate, and, although the pipes in 
places were laid on a steep hillside, they were not disturbed 
by heavy rain. In my notes of 1912 I find: "The fact that I 
saw it after four days in which 5-01 inches of rain had fallen, 
with one shower of 2-44 inches in forty-five minutes, shows how 
thoroughly the work has been done. Not only had the whole 
system withstood the heavy rainfall without suffering the least 
damage, but all the finished portion was completely dry within 
twenty-four hours of the rain ceasing." 

The result of this excellent work was soon seen in the 
improved health of the children and labourers. 



Year. 


Number of 
Children Examined. 


Spleen Rates. 


1912 
1913 
1914 
1915 


91 
III 

131 


50'0 
42-8 
29.7 
106 



The death rate showed a similar improvement. 



Year. 


Labour Force. 


Death Rate. 


igil 


373 


160 


1912 


492 


68 


1913 


501 


24 


1914 


520 


13 


1915 


500 


10 



MALARIA ON A HILLY ESTATE 255 

The births increased from two in 191 1 (both children died) 
to nineteen in 1914; and the European health also improved. 

In 1918 I was asked to visit the estate again, as the health 
had become bad. The two Europeans on the estate were 
constantly down with fever, and another was on leave on 
account of it. 

The spleen rate showed an increase as follows : — 





Year. 


Number of 
Children Examined. 


Spleen Rates. 


Children on the old site near the \ 
hills / 

Children farther from the hill (a \ 


1915 
1918 

1918 


135 
IOO 

18 


10-6 
43-8 

16-0 



Deaths. — There had been twenty-nine deaths for the first 
eight months of 191 8, giving a death rate per annum for 
working coolies of 64-9 per mille against 10 per mille in 191 5. 
In addition, nineteen children had died. The admission rate 
to hospital had increased, and additional hospital accommoda- 
tion had been erected at considerable cost. " The cause of the 
recrudescence: On revisiting the main ravine next the lines, 
which used to be the chief source of A. maculatus, it was 
evident that the importance of maintaining the anti-malaria 
work had not been fully realised. A considerable amount of 
water was still coming from the pipes, which had thus stood 
the test of six years' use without taking much harm. But 
probably half of the water from the ravine was coming down 
an open channel scoured out by the storm water. In some 
places there were probably pipes blocked by silt, but on the 
whole, from the amount of water discharging from the pipes, 
it would appear that blocking is comparatively slight." Oiling 
was being done with a not very effective hand sprayer ; and on 
my visit, I found the oiling coolie fast asleep in the upper part 
of the ravine. 

The war had thrown special work and responsibility on the 
manager ; and, through shortness of staff, insufficient attention 
had been given to the anti-malaria work. 

On my pointing out these things, the drainage and oiling 
were again made efficient, and the health rapidly improved. 
Writing in June 1920, the Estate Medical Officer says, "The 



256 THE REAPPEARANCE OF MALARIA 

work on the main ravines is all in good order," " leads and 
road drains are now being made thoroughly and systematically 
oiled." He reports the spleen rates as follows : — 



Year. 


Number of 
Children Examined. 


Spleen Kates. 


1919 

1920 ■ 


133 
171 


9-0 

3-5 



From these figures it is evident that the health has become 
practically normal again. 

VI. 

Another example of the reappearance of malaria on a hill 
estate is given in Chapter XVIII. in the notes appended to 
Fig. 63. Here the malaria came from the ravines of a newly 
opened estate which adjoined estate " SC." 



CHAPTER XXIII 

SCREENING 

(1909). — In October 1900, a Beri-beri Convalescent Hospital at 
Jeram was opened. It is on a stretch of sandy shore. But at 
Jeram, as in Italy, the shifting sand is continually blocking the 
drains, so much so that one tide will undo a week's work. In 
fact, the task of keeping them open was abandoned, and the 
water was led off by a circuitous route. The result was that 
the patients suffered from malaria. When I took charge in 
January 1901, I went through all the case sheets of the patients 
who had contracted the disease and tabulated the results. 
From 1901 to 1907 the record was kept continuously. The 
population was under complete control ; its number was 
definitely known, and in many ways it presented a very 
satisfactory field for observation. 

The patients were provided with mosquito nets from the 
beginning, and yet, in spite of these, they continued to suffer 
from malaria. 

It was then decided to make the hospital mosquito-proof. 
This appeared in the estimates for 1902 and was actually 
completed on the 17th November 1902. The gauze was 
of iron wire ; the sea air rusted it, and on the night of 
nth October 1903, a strong wind carried it away. It was 
never replaced. From 1st January 1905, no malaria case was 
admitted into the hospital, in order to see to what extent the 
local admissions of malaria influenced the spread of the 
disease in hospital. From the beginning of 1906 all the 
beri-beri patients were on a weekly dose of 10 grains of 
quinine. 

In this way I have tried to gain some idea of the 
relative importance of some of the factors influencing the 
epidemic. 



258 SCREENING 

The following are the figures obtained : — 

Table showing the Number of Beri-beri Patients attacked by 
Malaria at Jerani. Daily average about 50. 



Condition of Hospital. 


Mosquito 
Nets only. 
Oct. 1900 to 
Nov. 1902. 


Ward 

Mosquito. 

Nov. 1902 to 

Oct. 1003. 


Mosquito 

Nets only. 

Oct. 1003"to 

Dec. 1004. 


Malaria Cases 

not admitted. 

Jan. 1905 to 

Dec. 1906. 


Number of months 

Number of patients attacked 

Average number attacked 
per mensem 


26 

75 
2-87 


11 

5 
0-45 


15 
48 

3-20 


12 

20 

1.66 



It is to column No. 3 particularly to which I would direct 
attention. It will be seen that malaria was greatly reduced by 
the use of the gauze, and increased at once when the gauze was 
removed. That any malaria occurred is probably due to the 
purposely lax conditions which prevailed. No restraint was 
put on the patients to be indoors after sunset. Two double 
doors permitted entrance and exit after 6 P.M., and the patients 
often wandered to the native village only about a quarter of 
a mile away. 

I was proposing to prevent the possibility of outside infection 
by looking the hospital after 6 P.M. when the storm put an end 
to the experiment. 

The value of this experiment in my eyes is that the con- 
ditions were lax enough to permit of their being applied to 
coolies on an estate, or to coolies engaged on Government 
construction work, such as the making of railways or water 
works, where malaria is as great a scourge as it is on the worst 
estate. 

With these results I accordingly approached the Government 
in 1904 with a suggestion for an experiment on the above 
lines, on the proposed extension of the Klang Water Works. 
Dr E. A. O. Travers supported the suggestion, and Government 
instructed the State Engineer to include my requirements in 
his estimates. 

An Estate Experiment. — There was some delay in the 
preparation of the plans of the new works ; and the Govern- 
ment then, at my suggestion, sanctioned a special vote of 



AN ESTATE EXPERIMENT 259 

$2000 (about £24.0) to be spent on mosquito-proofing lines 
on an estate. I chose the most unhealthy spot I knew. The 
object of the experiment was, of course, not to test the mosquito 
theorem, but to discover whether lines could be built which 
would be sufficiently mosquito proof to reduce malaria, and 
yet would be acceptable to the ignorant coolie and in which 
he would be willing to live. 

The spot chosen for one of the lines, the only one to 
be completed, was on a saddle at the head of two ravines, 
one of which was opened and drained by the estate, but still 
contained A. maculatus, and the other was unopened and 
undrained jungle. There had been trouble in building the 
lines originally ; two contractors who tried to build the lines 
died from malaria since they refused to take quinine, and the 
first gang of coolies who inhabited it were practically exter- 
minated by malaria. All children under the age of fifteen 
were found to be infected with malaria on blood examination. 
These coolies were soon removed. Ultimately the lines were 
finished. No coolies on the estate would inhabit them ; and 
further, it was desirable to put in new coolies who presumably 
were free from malaria. A gang of coolies was put in during 
November 1907. 

They were not given quinine daily like the other coolies, 
but were carefully examined by the dresser of the estate, and 
I paid as many visits to them as possible. Unfortunately my 
health was not satisfactory at the time, and I had to go on 
leave. Before going, however, I was able to determine that 
it was impossible to find anophelines or other mosquitoes 
within the lines, 'although my observations, extending over a 
year, had shown that before proofing it was always possible 
to take about ten anophelines by looking through all the 
rooms, and other mosquitoes were much more numerous. The 
mosquito proofing, therefore, certainly succeeded in reducing 
the number of anophelines within the lines. 

Within a short time the coolies became aware of the char- 
acter of the lines they were in, and asked to be removed. 
On one occasion I was told by a coolie that on the previous 
night a devil had been heard knocking on the walls. 

I am unable to give any evidence as to the termination 
of the experiment. The manager stated that, as long as the 
coolies were there, they did not suffer from malaria, but that 

T 



260 SCREENING 

on account of their terror it was impossible to keep them there 
for long. He strongly suspected they left the lines at night and 
went to other unprotected lines. He also informed me that 
the coolies said the lines were very hot, and that at night 
they would often lie outside in a blanket. The lines had a 
wooden ceiling, and as they were more enclosed than other lines, 
it is probable they were hot. 

I had unfortunately to leave this experiment, and therefore 
am unable to draw any conclusions. Doubtless the F.M.S. 
Government will take an early opportunity of testing the 
value of mosquito-proof lines on the railway extensions now 
being carried out towards the Siam States, where malaria will 
doubtless be as serious an obstacle as it has been in the previous 
railway and other public works. 

(1920). — Although I suggested to the Malaria Advisory 
Board that it should undertake an experiment with screened 
lines, nothing has been done. 

Screened Houses. — On a malarial estate in Johore where 
there were difficulties in getting healthy sites, I recommended 
that a bungalow and servants' quarters be screened. The 
manager was afraid that it would be uncomfortable, and that 
he would feel "cribbed, cabined, and confined" in it. However, 
I advised the whole building should be done ; only two doors 
opening to the outside were to be left. There being no internal 
screened doors, the occupants could move about in the house 
as usual. 

A year's trial convinced the manager that his fears were 
without foundation, and that screening was of value ; and 
three other bungalows on the estate were screened. This was 
in 1914; since then, sixteen bungalows on other estates in 
the neighbourhood have been screened, which is the most 
satisfactory proof of the value of screening. 

Dr Hickey, the medical officer of these estates, sends me 
an interesting letter full of details, from which the following 
are excerpts : — 

" As regards screened houses, there has never been any 
doubt in my mind about their success. Not only on Segamat, 
but on Labis, Jenang, Genuang, Rubber Estates of Johore, 
and Johore Rubber Lands, Batu Anam, they have proved a 
success. 

" I know what a difference screening has made to my 




Fig. 85. — Mosquito-proof Coolie Lines. 

Under the atap (palm leaf) roof there was a wooden ceiling. The verandah 
was closed by weather boarding for about three feet, and to the ceiling by iron wire 
gauze. There were two doors closed by spring hinges. 



[To Jace page 260. 



SCREENED HOSPITALS 261 

bungalow; in 1912 and 1913 I suffered a good deal from 
malaria." 

Other anti-mosquito measures are employed on the estates, 
which have improved their health, but Dr Hickey adds : — 

" I quite realise that malaria is gradually becoming less 
prevalent on the estates here, but the improvement in the 
health of those who occupy screened houses is really wonderful. 
Men ask for screened houses now." 

Screened Hospitals. — On an estate where many anophelines 
exist, the malaria patients in hospital are a reservoir of parasites 
which soon infect the anophelines. These infect and reinfect 
the malaria patients, as well as patients coming in with other 
diseases ; nor do the hospital staff escape. Consequently the 
administration of the hospital becomes difficult; and patients 
recover slowly, if, indeed, they do recover. 

Protection from the insects is, therefore, a necessity. At 
first this was attempted by mosquito nets over the beds ; but 
with natives the nets are ineffective, and it is usual to find 
a number of mosquitoes within them each morning. In 
fact, these nets are so effective as traps that, when I desire 
to get specimens of adult insects in a place, I search the nets 
at daybreak ; for I know of no better way of getting a haul. 

In view of the failure of the nets, in 191 1 I advised an 
estate to screen its hospital. This was done, proved a success, 
and now there are screened hospital wards on six hill estates 
where malaria at one time was severe. Only one door is 
allowed at each end of the ward in which it is rare to see an 
insect. If any get in, they are caught in a bottle containing 
a plug of cotton-wool sprinkled with chloroform. 

The plan, kindly supplied by Messrs James Craig, Ltd., who 
have built several of these hospitals, shows the details of the 
ward. One or two points call for comment : — 

First. It is important that the screening of the jack roof 

be by two vertical strips of gauze, and not by a horizontal strip 
as first suggests itself; for a horizontal strip catches and retains 
much dust, while vertical strips are relatively self-cleansing. 

Secondly. — The doors should open outwards only, so that 
any mosquitoes resting on them are driven outwards when 
the door is opened. Double doors have not been found 
necessary. 



>62 



SCREENING 



Thirdly. — The drain must be inside the ward, as it is not 
possible with this design to wash the floors, and allow the 
water to escape under the side walls of the ward. 

Fourthly. — Attempts were made to retain a screened space 
of 6 or 8 inches along the floor of the ward ; in some hospitals 
the screening was on a hinged frame, in others it was fixed. 
The hinged screening has been most unsatisfactory ; the fixed 
screening rather less so. In future I would have no screening 
within a foot of the floor ; because it is liable to be damaged 
when the floor is washed. 

Fifthly. — In Panama nothing but an almost pure copper, 
or alloy free from iron, withstood the climate ; this was due 
to the screening being used on the outside of the verandah 
and exposed to rain and sun. In some hospitals here, the 
gauze used has been iron ; it is placed so as not to avoid 
rain or sun, and is standing the climate well ; indeed, in one 
hospital the gauze originally supplied in 191 1 is still in use, 
and it has not yet been necessary to renew it in any hospital. 
The cost of screening a hospital depends on the area and the 
cost and quality of the gauze. 

As a result of my experience of screened hospitals here, 
and from what I saw in Panama, I am strongly of opinion 
all native hospitals in this country should be screened instead 
of being supplied with mosquito nets. 



Screened with copper gauze 



Ceiling 'A Meranti Planks 




3", 3",%" 
*" T. Iron 



|*^5'o " > | < 



24 

SECTION 

Fig. 86 (a). 



SCREENED HOSPITALS 



263 








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CHAPTER XXIV 

ON DRAINAGE 

FOR the control of mosquitoes and malaria, land drainage in 
some form or other is so often required that the medical officer 
should learn at least the principles of this art, just as he 
learns the entomology of the disease. To most medical men 
the subject is a closed book ; few engineers have studied it 
in relation to malaria prevention. In the tropics the engineer 
has responsibilities in connection with roads, water-supplies, 
electric-lighting, bridge-building, and other branches of a great 
and highly specialised profession ; and it would be unreasonable 
to expect of him familiarity with the entomological aspects 
of drainage until these had been demonstrated to him. Yet 
the co-operation of the engineer and the medical officer is 
essential for a successful result ; and co-operation cannot take 
place unless each understands something of the other's point 
of view. The engineer should learn something of entomology ; 
the medical officer something about drainage. So a chapter 
on drainage as an anti-mosquito measure may be helpful ; 
and, as an American engineer tells us, " There is no mystery 
connected with the theory and practice of land drainage, as 
some would have us believe ; neither is there an instinct born 
in men which will relieve them from acquiring knowledge of 
this work in the old-time way." 

The Composition of Soil. — The soil 26 consists of particles 
of the rocks forming the earth's crust ; sometimes it overlies 
the rocks from which it came ; sometimes it is composed of 
particles which have been carried by water far from their 
original source, and in ages long gone by. The particles vary 
in size, weight, and arrangement ; between them are air or 
" pore " spaces ; and the weight of the soil depends on all 
these factors. Sand particles being large and heavy are easily 
consolidated and contain a smaller amount of "pore" space 



THE COMPOSITION OF SOIL 265 

than clay. Clay particles are relatively small and light, and are 
not readily consolidated, and have a higher "pore" space than 
sand. Although a clay soil is commonly called " heavy," it is 
not really heavier than a sandy soil ; the expression *' heavy '' 
having reference to the difficulty of drawing a plough through 
it. The "pore" space in sand comes down to 25 or 30 
per cent, of the whole ; and in a " stiff clay " rises to over 
50 per cent. 

In addition to the particles of earth, soil contains water 
in varying quantity. Some of the water is so closely associated 
with the particles that it can only be driven off by heating 
much above the air temperature, and it is reabsorbed from the 
air, when the temperature is allowed to fall to normal. This 
is the hygroscopic moisture ; it is not available for plant life. 

In addition, each particle of soil is usually surrounded by a 
thin film of water which maintains itself by "surface tension"; 
that curious condition which allows us to blow soap bubbles, 
and causes water to climb up the sides of a glass, so that it 
stands above the general surface level of the fluid. When 
particles of soil, surrounded by this capillary water, are in 
touch with each other, the water exercises a powerful binding 
force. To its presence is due the fact that damp sand can be 
moulded into shapes which fall to pieces when the sand 
becomes dry. 

The capillary water occupies very little of the "pore" space, 
for the thickness of the water film is hardly measurable ; nor 
can this water move through the soil. When more water is 
added to the soil, the film over each particle becomes thicker ; 
this surplus water can move upwards to the surface when 
there is evaporation, downwards to the subsoil water or "water 
table" and to drains, if the land be drained. 

When still more water is added, the surplus passes down- 
wards until, at a varying depth in the soil, all the "pore" 
spaces are filled. This is the level of the " water table," 
a level that varies according to the amount of water in the 
soil, which again depends on drainage and rainfall. 

When the "pore" spaces are filled with water, the thin 
film round each particle of soil no longer exists, the particles 
are no longer bound to each other by the " surface tension " 
of the film, and they may easily move on each other. Hence 
wet sand is almost fluid ; and swampy land is soft. 



266 




ON DRAINAGE 

It is the control of this sur- 
plus water, and the level of the 
" water table," which are of in- 
terest and importance to the agri- 
culturist and to the sanitarian. 

How a Drain Acts. 27 — If the 
question be put to someone for 
the first time, " How would you 
drain an acre of land ? " the 
answer will almost certainly be, 
" Dig drains through it.'' The 
right answer is, " Dig drains 
round its sides " ; for, having 
done so, it will be found as a 
rule that the land is dry. The 
level of the ground water will not 
be at an even depth throughout 
the whole acre ; it will be lowest 
next the drain, and highest in the 
centre of the block. Only if the 
level of the water in the centre 
be still too high for the object 
in view, whether it be agriculture 
or a mosquito control, is a drain 
cut through the centre. 

When land is drained, the 
water begins to move towards 
the drain, as is shown by the 
arrows in Fig. 87. 

The farther the water has to 
flow in order to reach the drain, 
the greater is the friction, and 
the slower it is in getting 
away, and the longer the water 
table remains high. If it be 
necessary to lower the water-level 
still more, the drains may be 
deepened ; but in a stiff soil this 
may lead to the land next the 
drain being over-dry, and the 
centre of the block still very 



THE RESULTS OF DRAINAGE 267 

wet. In that case another drain may be cut through the 
centre. 

It will be understood that when there is a drain at A and C 
only, the undrained soil must be highest at B, the point farthest 
from the drains ; but if an additional drain be placed at D, then 
the highest levels of the water will be found at E and F. The 
water, as a whole, will then be farther below the surface, and 
the land better drained. See Fig. 88. 



*.., AJ\U\ll.dAL A. huK)Lk,.),Ai^ l'« AMi,Jh.A. %,«.>\«Ah„\ 




FlG. 88. — Diagram of Influence of Distance between Drains on Depth 
of Drainage. (After King.) 

The Results of Drainage. — The results of draining land are 
numerous, and need be referred to here only very briefly. 
Drainage removes an excess of water, which is replaced by 
air ; not permanently, however, for each fall of rain refills 
the " pore " spaces with water that in its turn again gives 
place to air. This is the aeration of the soil, so important to 
the agriculturist. Without it the organisms, which convert the 
oxygen and nitrogen of the "pore" spaces to the use of plants, 
cease to work; the plant dies, and is replaced by the swamp 
grasses and plants with special adaptations to make soil air 
unnecessary. To the anti-mosquito worker the drying of the 
soil is no less important ; it allows rain to be absorbed, instead 
of standing in pools, or making the land a swamp. 

Drainage sweetens the soil, as the farmer says. In some 
countries it removes the excess of alkali which makes the land 
entirely unfit for agriculture ; in peaty lands it removes the 
excess of peaty acids, no less injurious to most plants of value 
to man. These changes come from the movement of the 
water ; stagnant water allowing excess of acid or alkali to 
accumulate. Drainage hardens the soil. It allows men, and, 



268 ON DRAINAGE 

it may be, cattle and vehicles to move over the surface 
without inconvenience or without making deep impressions 
in the ground, which expose the ground water and form 
mosquito breeding-places. As we have seen, when a soil is 
saturated with water, there is little cohesion between the 
particles, and so they are easily moved ; when land is drained, 
the soil particles are bound together by the thin films of 
capillary water that surround them and are not easily moved. 

Many other changes occur in drained soil, such as an 
increase in the temperature, which are important to the 
agriculturist, but need not be considered by the sanitarian 
at the moment. 

Subsoil Drainage. — At first drainage was probably carried 
out by shallow surface drains ; later, these would be converted 
into trenches. But as land increased in value, and the number 
of trenches had to be multiplied, subsoil drainage was invented. 

Poles and Faggots were laid in the drains, which were then 
covered over, so that the surface of the land was uninterrupted. 
Needless to say, the drainage by these was not very permanent, 
except under special conditions. 

Stone Drains were an advance on poles and faggots. 
Sometimes the drain was simply half filled with small stones ; 
sometimes a flat stone was placed horizontally over the small 
stones, or larger flat stones were placed on edge in the bottom 
of the drain, from which was evolved the system of putting 
down three flat stones to form a triangle with a channel 
between them. But stone drains were expensive ; and in 
time they were replaced by the tile or pipe drain ; for a 
cartload of pipes went as far as a hundred cartloads of stones. 

The Pipe Drain. — The drain pipe itself has undergone 
various modifications. In its earliest form, the pipe or tile 
was made singly, and by hand. The clay was rolled out and 
then pressed over a block into the shape of a horse-shoe 
(Fig. 89) ; and in using these horse-shoe tiles it was only deemed 
necessary to lay them on a hard bottom of clay. It was soon 
found, however, that this was not enough. The run of the 
water wore the bottom of the drain and softened the clay, till 
the tiles were either displaced altogether or sank into the 
bottom, and the drain became useless. The next improvement 
was to make the tile with feet, as in Fig. 90, in order to prevent 
it sinking into the earth or clay on which it rested. An obvious 



THE CYLINDRICAL DRAIN PIPES 269 

improvement on this, however, was to set the horse-shoe tile 
upon a flat sole, a little wider than the tile itself, as in Fig. 91. 
When placed in position the possibility of the tile sinking into 
the earth was overcome, and at the same time a solid run was 
provided for the water which flowed through the drain. 

" The Cylindrical Drain Pipe.- — The sole-and-tile was in turn 
superseded by the machine-made pipe, in which the horse-shoe 
form, as in Fig. 92, was at first closely adhered to, but this has 
now been entirely superseded by the cylindrical pipe shown in 
Fig- 93> which possesses many advantages. It forms a complete 
conduit in itself; it is stronger than any other form of pipe; its 
extreme lightness makes it very easy of transport, and owing 
to its small diameter a less quantity of earth need be excavated 
in digging a drain for a cylindrical pipe, at a given depth, than 
for any other drain material." — (Scott). 

nnnoo 

Fig. 89. Fig. 90. Fig. 91. Fig. 92. Fig. 93. 

These Figures show some Stages in the Evolution of the Subsoil Drain Pipe. 

Pipe Collars were at first generally used to join the ends of 
the pipes ; these were short lengths of a pipe wide enough to 
admit the ends of the pipes forming the drain. But they have 
gone out of use, as an unnecessary expense, except possibly in 
very peaty soil. 

"How Water enters the Pipes. — The question 27a ' How does 
water enter a drain pipe when it is laid 3 or 4 feet deep 
in the soil?' is often asked by beginners. From experiments 
which were carefully carried out by Mr Josiah Parkes, in order 
to determine this point, it was found that under a pressure of 
4 feet of soil the absorbent power of various pipes formed of 
various soils was equal to the passing of about one five- 
hundredth part of the quantity of water which enters the 
conduit through the crevice existing between each pair of 
pipes. By so much, therefore, the porous nature of the pipe 
material is useful; practically, this influence is so small that 
we may regard the whole of the water as entering at the joints, 
but the greater portion of it enters the drain pipes from below. 

" In all soils requiring drainage there exists a water-table 



270 ON DRAINAGE 

or level of supersaturation, and in a well-drained soil this level 
corresponds with the level of the drain pipes. When rain falls 
on the surface, the water finds its way downwards till it reaches 
this water-table. It then begins to rise, and if the drains are 
sufficiently active the pipes will carry off this rise of water as 
fast as it enters them from below. If the water rises above the 
level of supersaturation faster than the drain can take it off, 
then of course the pipes become completely swamped, as it 
were, and the water enters at every part of the joints. When 
the rain has ceased to fall, however, the continued action of 
the drain will soon suffice to again reduce the water of 
supersaturation to its proper level ; water will even cease to 
flow from the drains until more rain falls, and then the same 
thing will go on as before, the height to which the free 
subjacent water rises being wholly dependent on the activity 
of the drain, and the sufficiency of the pipe to carry off the 
water from it in a given time. 

" That the water will be freely admitted to the pipes at the 
joints is easily shown. With 2-inch pipes, when laid as close 
end-to-end as possible, the opening between two of them is 
usually not less than one-tenth of an inch on the whole 
circumference. This makes six-tenths of a square inch opening 
for the entrance of water at each joint. In the length of a 
drain between any two points, say ioo yards distance, with 
pipes 12 inches long, there will be 300 joints or openings, 
each six-tenths of a square inch in area, or a total of 180 square 
inches for admitting water to the drain. The area of the outlet 
from a 2-inch pipe is, however, only about 3 inches, so that the 
inlet area is nearly sixty times greater than the outlet area." 

The Drainage of Ravines. — In an early chapter (II.) I 
pointed out how money had been spent needlessly in the 
town of Klang in " filling in " swamps at the foot of hills, and 
how these swamps could be dried by intercepting the water 
coming from the hills by a hill-foot drain. In ravine drainage 
the same principle is applied. In narrow ravines a pipe along 
each hill foot may be sufficient, but in the wider ones and 
longer ones a central line of pipes is also required. The 
method of laying them so that they are not disturbed by storm 
water has already been described in the chapter on Seafield 
Estate. 

Roots of rubber trees grow into subsoil pipes, just as the 



MEMORANDUM ON MALARIA 271 

roots of many water-loving trees grow into pipes in England. 
To guard against this, the ravine should either be cleared of 
rubber trees, or the pipes opened at once, if there be evidence 
of blockage, and the roots removed. 

It sometimes happens that a long ravine begins beyond the 
sanitary circle and runs through it ; and that only from the 
point it enters the circle is subsoil drainage required. So far 
no really satisfactory way of draining such a ravine by pipes 
has been discovered. Attempts have been made to pass the 
water from the upper and open part of the ravine into the 
subsoil pipes of the lower part through rough stone filters ; 
but silt has blocked them so frequently that they have become 
usually but not always useless. It has generally been found 
necessary to carry the stream down in a cement channel, or 
to oil the whole ravine. 

A Demonstration at Klang. — When' the sanitarian begins 
mosquito control in a town he will find many difficulties in 
putting the principles of correct drainage into force. Almost 
at every step he will be tempted to make some compromise ; 
the engineer may not quite grasp what is required ; and before 
he is aware, the sanitarian may find himself saddled with a 
system of drainage which he can only regard as something 
considerably below the standard he intended to attain. At 
least that has been my experience. So when asked in 191 1 to 
advise the Municipality of Singapore on the control of malaria, 
I suggested that the officers who would carry out the work 
in Singapore should come to Klang for a demonstration. The 
points discussed were subsequently embodied in my report, and 
are republished now in the hope that they may be helpful. 



MEMORANDUM ON MALARIA IN THE DISTRICT 
OF TELOK BLANGA, SINGAPORE. 

By MALCOLM WATSON. 

A Preliminary Demonstration at Klang. 

1. When invited by your Anti-malaria Committee to proceed 
to Singapore and advise on the anti-malaria measures to be 
adopted, I at once suggested the advisability of a preliminary 
visit to Klang of your own officers, who would eventually be 



212 ON DRAINAGE 

responsible not only for the local investigation of the disease, 
but also for the necessary engineering works. 

2. My object in proposing this visit was that those upon 
whom would be thrown the duty of recommending and of 
carrying out remedial measures, should have an opportunity 
of seeing for themselves the anti-malaria works which have 
been adopted at Klang and at Port Swettenham, and of 
becoming acquainted with districts where the malaria conditions 
have been the subject of study for some years. 

3. Malaria in the F.M.S. has been found to disappear from 
areas of low-lying land where the ground water lies very high, 
and where there exist what would appear to be dangerous 
mosquito breeding-places ; while on the other hand many hill 
areas are intensely malarious, although the only water to be 
seen consists of springs and of clear running streams. 

4. It occurred to me that a visit to such areas would be of 
infinitely greater value than many pages of descriptive writing. 
I could thus, moreover, take this opportunity of demonstrating 
the details and essentials of land drainage, and of pointing to 
some of the errors (which were perhaps unavoidable) in the 
pioneer work done here, the repetition of which in Singapore 
I was anxious to prevent. 

5. The officers selected for this visit were Drs Middleton 
and Finlayson and Mr Ball. They spent three days in 
examining these areas : — 

(i.) Hill-foot Drains. — In the town of Klang the system 
of hill-foot drains was seen, and special attention was 
called to the importance of draining at as low a level 
as possible ; the higher up the hill the drain is cut, 
the greater the excavation, and consequently the 
greater the expense, while the lower the drain and 
the nearer it is to the edge of the swamp, the more 
effective it is, both in cutting off from the swamp all 
water coming from the hill, and also in withdrawing 
water from the swamp. 

Where a spring appears on the side of a hill some distance 
above the hill-foot drain, the most economical way of dealing 
with it is by cutting a lateral drain from the hill-foot drain 
up to the spring. 

(ii.) Dangerous Swamps drained by Earth Drains. — In Klang 



MEMORANDUM ON MALARIA 273 

the dangerous hill-foot swamps were, and still * are, 
drained only by open earth drains. These have been 
found sufficient, and are, of course, much less expensive 
than brick or masonry drains. Originally the whole 
anti-malaria drainage system at Klang (except the 
main outlet which took sewage) consisted of earth 
drains, and it was by means of earth drains that 
Klang town was freed from malaria. Gradually the 
system of earth drains is being replaced by brick 
drains, and as these have too often been constructed 
with more regard to some ideal " grade " than 
to the requirements of the ground through which 
the drain passes, I have no hesitation in saying that 
the actual land or anti-malarial drainage of Klang is 
less effective now with its brick drains than it was 
eight years ago with its earth drains. I would even 
go further and say that, if a close watch be not kept 
on the level at which brick drains are laid down in 
Klang, the hill-foot swamps will reappear (as two 
now threaten to do), and malaria will recur in the 
town. 

It is important, therefore, constantly to bear in mind that 
a brick drain is unnecessary in the eradication of malaria on 
flat land in this country or for draining swamps at the foot 
of small hills. Not only does a brick drain add greatly to the 
original cost of the work, but, unless graded with care and due 
regard to the surrounding land, it may actually hinder effective 
drainage. 

(iii.) The Grading of Brick Drains: — 

(a) The explanation of the current practice in putting 
brick drains down with a steeper gradient than the 
original earth drain is to be found in the necessity 
of laying a sewer with a stiffer gradient than a drain 
carrying only clean water from land drainage. 

(o) Brick drains are not as a rule laid down in this country 
except in towns ; and then only in places where a 
considerable population has so polluted an earth drain 
that it has become a stinking stagnant mass, more 
akin to a cesspit than a channel carrying off sewage. 
On the advantages of substituting for such a stagnant 
channel a self-cleaning brick drain it is unnecessary 
for me to dwell. 

* Subsoil drains were subsequently laid down when A. maculatus 
appeared in Klang in 1913. 



274 ON DRAINAGE 

(c) Experience has shown our engineers that a steep gradient 

is necessary if such a brick drain is to be satisfactory 
and self-cleaning, and it has consequently become 
a rule that such drains 9-inch to 12-inch diameter 
shall be laid down with a gradient of about 1 in 100, 
unless they be of abnormal size. 

There is no question that this is sound practice for brick 
drains when they carry sewage. 

(d) It must not be forgotten that engineers have an 

additional reason for insisting on a steep grade for 
sewers in this country. Although we have heavy 
storms to scour out our sewers, the average composi- 
tion of sewage in a brick drain in this country is 
much more concentrated than in England, because 
the absence of water-closets, of baths, and of house- 
to-house water-supply reduces the quantity of water 
employed in a tenement, and the domestic waste 
water or sewage is thus not diluted to the extent 
to which it usually is in England. 

(e) The greater the concentration of sewage, the greater 

difficulty it has in finding its way along a channel ; 
consequently the gradient of the channel must be the 
steeper according as it is to be the more self-cleansing ; 
(and all channels carrying sewage should be self- 
cleansing, whether classed as sewers or brick drains). 
(_/) There are many swampy places in this country where 
a gradient of 1 per centum, carried up from the outfall, 
would bring the top end of the drain at such a level 
that it would be ineffective as a channel for draining 
the land through which it passes, the invert of the 
drain coming above the level of the ground. 

As an anti-malarial measure, it would be a pure waste of money 
to lay down a brick drain at such a level and with such a 
gradient, although it might be quite proper to do so, merely 
from the point of view of a sewage system. 

(g) It would appear, therefore, almost as if sewage and 
land drainage were incompatible. Undoubtedly this 
is so in many places. It should be the rule wherever 
possible to combine the two, for it is an advantage 
to carry off the land drainage water quickly by means 
of a brick channel, and a further advantage to be 
able to dilute the sewage by the land water, thereby 
expediting the flow of the sewage. 



MEMORANDUM ON MALARIA 275 

(h) It sometimes happens that in constructing a brick 
drain in place of an earth drain, either for the purpose 
of carrying off storm water, or as part of a sewage 
system, the level of the invert of the brick drain 
is the same as that of the original earth drain, and 
the swampy condition of the surrounding land is 
overlooked. If the brick drain has been put down 
at such a level that the swamp cannot be drained 
into it, and the brick drain is the only outlet for 
the drainage of the swamp, as is sometimes the case, 
then the swamp can only be drained by pulling up 
the brick drain and relaying it at a lower level. 

(?) I would therefore advise that no anti-malaria drain 
be constructed other than as an earth drain in the 
first instance. If such an earth drain be found to 
be inefficient through being insufficiently deep, then 
it is an easy matter to deepen it. If, on the other 
hand, a brick drain be put down and the surrounding 
land be still found swampy, the deepening of the brick 
drain involves the heavy expense of reconstructing 
it at a lower level, and at even greater expense than 
that of the original drain. 

(J) Where the sewage must be at a higher level than the 
land drain, it may be possible, when we have had 
more experience of underground drainage, to combine 
the two systems with advantage. A system of under- 
ground pipes might very well drain the land at the 
sides of a brick sewer ; the sewer, being laid with a 
steeper grade than the subsoil drain, would soon reach 
a level that would enable the subsoil drain to discharge 
into it. I have mentioned this only as indicating the 
line in which an advance can be made, and a difficulty 
overcome. While for anti-malarial drainage a brick 
drain is not essential, it is nevertheless an advantage 
to have the land water carried off quickly. And 
equally is it an advantage in this country to dilute 
the sewage with land water so that it flows more 
freely. 

(/•) There is a further advantage in replacing earth drains 
by some self-cleansing system, either closed pipes or 
brick drains, namely, that diseases other than malaria 
are carried by mosquitoes. Not to mention dengue, 
the mosquito carriage of which may be open to 
question, the subject of "Filaria" is one of the gravest 
moment, and it is one which is certain to engage 

U 



276 ON DRAINAGE 

more attention in the future. I will deal with this 
infra. 
(/) The visit to Port Swettenham showed how land could 
be freed from malaria by drainage even when it was 
below the level of high tide. The position and level 
of outlets protected by tide valves was discussed. 
There appears no reason why such outlets should not 
be one or even two feet below the level of half-tide.* 
The lower the outlet, within limits, the greater the 
reservoir of dry earth which can absorb rainfall until 
the outlet is opened by the falling tide. 

(iv.) Filling up a Swamp: — 

(a) In Klang attempts were made in more than one place 

to get rid of the water of a hill-foot swamp by filling 
it in with earth. They were failures. Filling might 
be a success if the earth were of a very pervious 
nature, so that the water from the springs which were 
the cause of the swamp could freely traverse the 
" filling," and travelling under it make its way to the 
nearest drain. 

(b) But "filling" in this country usually consists of a very 

impervious reddish clayey earth taken from a hill. 
To place such an impervious material on the top of 
the impervious bed of a swamp is merely to raise the 
level of the impervious layer, and to enable the water 
descending from the hill to appear at the resulting 
surface. The springs accordingly appear on the top 
of the filling, and spreading out on it continue to form 
important breeding-places for dangerous anopheles. 

(c) Not only is such filling ineffective, but it is very 

expensive, costing at least ten times as much as the 
earth drains which would effectively drain the swamp, 
and often much more. 

(d) There is another reason for draining a swamp in 

preference to "filling" it in. Owing to the expense 
of " filling," it is unlikely that more will be applied 
than is just sufficient to obliterate all traces of water 
from the surface. The ground water will therefore 
still be within a few inches of the surface. 

On the other hand the cutting of an extra depth of drain will 
lower the subsoil water at a very small cost, as compared with 
filling. 

(e) There is an advantage in lowering the level of the 
* 1920. They have been placed much lower since then. 



MEMORANDUM ON MALARIA 277 

subsoil water, namely, that the dry soil above the 
water forms a reservoir for rainfall. Two feet of soil 
may very well be able to absorb one-third of their 
volume of water ; in other words, will be able to take 
up eight inches of rain. 

Such drained land will therefore be much less liable to become 
swampy in very wet weather than the land which has been 
so " filled in " that the ground water even in dry weather is 
still only a few inches from the surface. 

(/) It is an old observation, made long before anything 
was known of the part played by the mosquito in the 
propagation of the malaria parasite, that, lowering the 
level of the subsoil water and the dry cultivation of 
the soil which then first became practicable, led to a 
disappearance of malaria. And it is well known that 
even in non-tropical and non-malarious countries, 
houses built on land with a low ground water are 
healthier than those on land where the water stands 
nearer to the surface of the ground. 

(g) If houses are to be built at all on the swampy land, 
I have no hesitation in saying that they will be 
healthier in every respect if the swamp has been 
drained, than if it has simply been " filled in." 

(k) Of course there are times when, and places where, to 
fill in and raise the level of land will add greatly to 
its value. And the money spent on such filling may 
be a sound commercial investment, which may be 
quickly realised in the market with great profit. Not 
to " fill in " under these circumstances would be to 
neglect an opportunity not only of adding to the 
area of land available for use, but also of making 
an addition to the revenue which may be employed 
advantageously in other directions. 

(«') Or, as in the case of the Tanjong Pagar reclamation, a 
great area may be added to a city, the occupation of 
which will relieve prevalent overcrowding of more 
central portions. Such a work has a sanitary value 
which can hardly be overestimated. 

To reclaim a dangerous swamp, to bring a labouring population 
near to its work, to house that population in buildings con- 
structed and maintained according to the highest sanitary 
standard, to add to the revenues not only a large annual 
sum from rent, but also a great asset of ever-increasing value, 



278 ON DRAINAGE 

all at one stroke, is a conception of sanitary statesmanship of 
the highest order. 

(v.) Mosquito-borne Diseases other than Malaria : — 

(a) There is another point of view from which the anti- 

malarial drainage of the land must be looked at. 
I refer to the other diseases which are carried by 
mosquitoes. The most important of these in this 
country is Filaria.* We know it occurs among 
Malayans in all parts of the Archipelago. Accord- 
ing to Manson, 10 per centum of Amoy's inhabitants 
harbour the parasite, and it is present only in a slightly 
less percentage in the Southern Chinese. Some parts 
of India are seriously affected, and so are places in 
Japan. These are countries which send many of 
their inhabitants to Singapore. 

(b) The disease is none the less serious because infection 

by the parasite may show no symptoms for many 
years. But the condition of the Fiji Islands where 
Filaria is present in 25 per cent, of the population, and 
elephantiasis is so terribly prevalent, is a warning 
that the ever-increasing immigration attracted to 
Singapore by its prosperity may be drawing unawares 
to the island and to the city unrecognised carriers of 
the disease, and a rude awakening may come to a 
knowledge of the fact that the disease is silently but 
none the less tragically spreading among the populace. 

(c) Year by year we see more clearly that along with its 

benefits Western civilisation, with its free system of 
communications, is introducing serious dangers in the 
form of increased liability to disease ; and the greater 
the populations and the freer the communications with 
other countries the greater is the danger. 

{d) Plague was carried to India at the end of last century 
by ships from the West. But for these, India would 
in all probability now be free from the disease. 
Indeed, in vast regions of India any benefits ever 
given by Western civilisation have been more than 
balanced by this disease. 
(e) Sleeping sickness is an example how in a few years a 
terrible disease can march across a great continent, 
keeping step with the white man in his progress, and 
cause such devastation that whole regions have to be 
abandoned. 

(/) Throughout the tropical cities of the world, the security 
* A worm whose embryos live in the blood. 



MEMORANDUM ON MALARIA 279 

from fire given by the more substantial house built 
under Western rule, is being paid for in an alarming 
increase in tubercle, 
ig) The great increase of malaria in Singapore is un- 
doubtedly due to the conditions produced by its 
increasing population and prosperity. It would 
surely be unwise to wait until a dreadful disease 
like elephantiasis is upon the city before taking 
steps to check its course. 

(ft) I would strongly recommend, therefore, that in such 
time as he can spare from his malaria work, Dr 
Finlayson should carry out an investigation into the 
prevalence of Filaria among the people. This can 
easily be done by having slides of blood taken from 
the inmates of the hospitals. For, while the drainage 
of swamps by means of open earth drains does away 
with probably 95 per cent, of the mosquito-breeding 
area, the very drains, especially if neglected, produce 
a few mosquitoes capable of carrying this disease. 

(i) While urging the use of earth drains for the purpose 
of eradicating malaria, I confess I regard them only 
as marking a stage in our progress towards the not 
far distant day when all breeding-places of mosquitoes 
within a town will be obliterated. In time it may be 
possible to replace the open earth drains by closed 
subsoil drains, thereby not only reducing the cost of 
upkeep, but rendering them impossible as breeding- 
places. 
(/) This, however, must be in the future, and only when 
from experience we can be sure that the subsoil pipe 
in this country has a reasonable life of usefulness. 
So far as I know there do not appear to be any special 
difficulties in using pipes in this climate. But before 
launching out on any large scheme it would be wise 
to give a small area a thorough trial. 

(£) If no unforeseen difficulties arise, the drainage of the 
future will be brick drains where there is sewage, and 
a system of subsoil drainage for the land ; the latter 
falling into the brick drains. Storm water will be 
carried off by shallow drains under which are the 
subsoil drains. Should a definite system of closed 
sewers be adopted for Singapore * with pumping 
stations at various places, it would obviously be more 
economical to deal with storm water separately. The 



280 ON DRAINAGE 

employment of subsoil drainage, connected with the 
sewers but independent of the shallow storm water 
drains, would in all probability facilitate the separate 
treatment of the storm water. 

6. I have endeavoured in the foregoing pages to place on 
record some of the points discussed at Klang and Singapore. 
It will be seen that the malaria problem, like most other 
problems, cannot be kept in a water-tight chamber. Measures 
for its eradication should be considered not only from the 
malaria aspect alone, but from its bearing on other questions. 

7. In dealing with malaria, and especially in spending 
money on measures for its eradication, every care must be 
taken that some other problem is not made thereby more 
acute or more difficult of solution. 

8. I would summarise the foregoing demonstration as 
follows : — 

(«) Do not spend money on filling in a swamp unless — 

(i.) You cannot drain it (a situation which will rarely 
be the case) ; or 

(ii.) You can see your way clearly to realise within a 
reasonable period the money so invested at a 
profitable return in either cash or health. 

(b) Don't begin by filling up the natural outlet when a 

swampy area must be filled up. This only aggravates 
the swamp, and it will be pure luck if an outbreak of 
malaria does not follow, or if already present, is not 
increased. 

(c) An open drain properly placed at the foot of a hill 

intercepting the water from the hill, costs a mere 
fraction of the filling which would be necessary to cover 
the water of a hill-foot swamp, and renders the ground 
drier, and less liable to revert to a swampy condition 
in wet weather, and healthier as a building site. 

(d) Only consider the question of filling in a swamp after 

trying to drain it. After your attempts it will often 
be found that the filling is unnecessary. Much waste 
of money will thus be prevented. 

(e) If an earth drain when first cut does not efficiently drain 

the swamp through which it runs, it is often possible to 
dig it deeper, at a very small additional cost. 



MEMORANDUM ON MALARIA 281 

(/) If a brick drain has been constructed, the cost of 
deepening it will be probably more than the original 
cost of the drain. 

(g) No anti-malaria drain should be piped or bricked until 
it has been proved to be thoroughly capable of draining 
the swampy land, through which it runs. If it cannot 
drain the water off as an earth drain, it will certainly 
be less efficient as a brick or piped drain. 

(h) An open earth drain will, except in hilly land, eradicate 
malaria. In the future it may be possible either to 
brick in, or pipe the drain, so as to render it harmless 
as a breeding-place for any class of mosquito. In the 
meantime, it is doing its work in eradicating malaria 
at a minimum cost, and it forms no obstacle to any 
system which may be desirable in the future. 



CHAPTER XXV 
ON MOSQUITOES 

One of the first difficulties confronting a medical officer who 
attempts mosquito control is the identification of the local 
mosquitoes, and even of the anopheles. When, after Ross's 
discovery that the mosquitoes carry malaria, the importance 
of the subject came to be recognised, Mr Theobald, 28 of the 
British Museum, undertook to receive, describe, and classify 
the insects sent to him ; and he published a series of volumes 
in the course of the following six or seven years. During 
the same period, a number of observers in different countries 
published descriptions of the mosquitoes taken by them ; with 
the result that few insects have escaped being described under 
one or more names. 

As time went on and new specimens were discovered, 
the distinctive characters originally employed to separate 
various genera and species were often seen to be connected 
by intermediate forms, and shaded off into one another, 
making classification a matter of difficulty and controversy. 
It has been confusing in the extreme to the student; and, 
for the beginner, has proved an almost insuperable obstacle 
to progress. 

Although considerable progress has now been made, and 
the synonymity of many species is worked out, it will yet 
probably be the simplest plan for a new worker to learn only 
the local species as species — without troubling too much about 
genera. It will be of the greatest advantage to him, also, if 
he can obtain some practical demonstrations of the insects 
from one familiar with the local species. This will save him 
many a weary hour, much wandering in the wilderness of the 
unknown, and may prevent him making serious mistakes. 

It is not my purpose here to attempt to describe the 
distinctive features of our local anopheles. The beginner 

282 



DR STRICKLAND'S OBSERVATIONS 283 

will find the two keys — of larvae and of adult insects — prepared 
by Dr C. Strickland helpful. After mastering these, he may 
proceed to the papers published by Drs Strickland - 9 and 
Stanton, 30 the names of which I give in the list of references. 
Dr Barbour's 31 paper on the infecting of the local anopheles 
must also be studied ; and the first of a new series of papers 
by Dr Hacker 32 on local malaria has been published. 

Here I purpose merely to make some general observations 
on the different anopheles and their relationship to malaria. 
In the course of this volume much has already been said on 
the subject; but there are some gaps which may with advantage 
be filled. 

In doing so I propose to utilise some of Dr C. Strickland's 
unpublished observations. During the period of his work in 
the Malay Peninsula, he carefully recorded his observations 
in such a form that they admitted of tabulation. He did so 
in order that, as far as possible, the study of the conditions 
in which mosquitoes lived, or did not live, might be put on 
a mathematical basis ; he aimed at giving something more 
than " impressions," and hoped to supply a scientific basis for 
any conclusions he might draw, and any general statements 
he might make. His observations deal with 15,165 breeding- 
places ; and as a large number of details of each breeding- 
place is recorded, and analysed, it will be realised how 
laborious the work was, and how valuable it is. General 
statements, such as that A. umbrosus is a pool breeder, or 
A. maculatus is a stream breeder, have been tested mathe- 
matically ; and it is now possible to see how far they are 
true or untrue. 

I understand Government does not propose to publish 
the report ; but as Dr Strickland has lent me a copy with 
permission to publish extracts, I gladly do so on account of the 
value of his observations, and of the important contributions he 
has made to our knowledge of mosquitoes, and the prevention 
of malaria in this country. 

A. ludlowi. — So much has been said of it in the chapter 
on "The Malaria of Mangrove Swamps and Anopheles ludlowi" 
that I will content myself with emphasising the one great 
practical point. At first sight the problem of its eradication 
seems insoluble. It is a prolific pool breeder ; perhaps the 
most prolific anopheles one meets. It breeds in almost every 



284 ON MOSQUITOES 

pool in the zone which it frequents ; tufts of grass, bits of 
stick, and every sort of obstruction are usually found to 
shelter it in enormous numbers. Cracks in mud, hoof marks, 
blocked drains are loved by it. 

The malaria it causes is shown by the high spleen rate ; 
its zone has acquired a world-wide notoriety for unhealthiness ; 
and it will be strange if there are not well-known local instances 
of its malignant power. The control of malaria in these 
circumstances may well daunt the bravest optimist. Yet I 
must insist that it can be controlled with ease by a simple 
system of clean, open drains ; and this had been demonstrated 
time and again in the Malay Peninsula. 

A. rossii (Giles) is comparatively rare, but does occur. 
It plays no part in the epidemiology of the disease in the 
F.M.S., as far as is known; just as it is a negligible factor 
in India. A. rossii var. indefinita is the common form here ; 
it, too, is not, I believe, of practical importance. 

The Umbrosus Group. 

In the original description, A. umbrosus was given with only 
one white spot on the costal vein of the wing ; but when I 
came to work with the insect I found a second spot so common 
that I designated it A. umbrosus var. x. There are now 
known to be several anopheles closely allied to it, although 
none are found in the profusion of A. umbrosus. A. umbrosus, 
as we saw, breeds in the inner Mangrove Zone, the Coastal 
Plain, the Coastal Hills; rarely, if ever, in the Inland Hills, 
although further research is required to map the line of its 
inland limit. 

A. separatus is not unlike A. umbrosus, but has white bands 
on its palpi, which at once distinguishes it. It frequents the 
coastal region like A. umbrosus. 

A. albotaeniatus also breeds in the inner Mangrove, is very 
rarely taken in the Coastal Plain, but seems to become commoner 
in the Coastal Hills, although even here it is rare. The character 
chiefly distinguishing it from A. umbrosus is the broad, white 
banding of the hind legs. It is not known to be a natural 
carrier of malaria. 

A. albotaetiiatus var. montanus may be called the umbrosus 
of the Inland Hills ; but in comparison with the number of 



THE UMBROSUS GROUP 285 

A. umbrosus found in the Coastal Plains it is a rare mosquito. 
It is like A. albotaeniatus, but has still more white on its legs. 
It is not known to be a natural carrier of malaria. Like 
A. umbrosus it is a jungle species, and Dr Hacker's observations 
would indicate that it disappears when the ravine is opened ; 
indeed the whole Umbrosus group just named are primarily 
jungle mosquitoes, living in pools, or very slowly streaming 
swamps. 

In his chapter on "The Mosquitoes of Virgin Jungle," 
Dr C. Strickland, after describing the dense shade through 
which "not a sunbeam filters," says : — 

"As for mosquitoes of any sort they are very rare; all 
travellers in the virgin forest testify to it. Travellers will 
sleep there with impunity and not be bitten by mosquitoes. 

" But it is only in certain parts of the virgin forest, those 
parts which lie on the uplands and on the mountains. If the 
traveller enter the forest on the flat land he will certainly be 
attacked by species of the timbrosus type, by Mansonia species, 
and Stegomyia scutellaris. 

" During the rainy season the little pockets among the 
roots of the trees on the flat forest land become filled with 
small pools, if the land is not actually under flood from the 
neighbouring rivers. In such collections of water umbrosus 
will be found breeding. On the hills, of course, no such 
breeding-grounds form. 

" During the dry season the shallow valley beds, on the 
flat land and between the hills on the low hill-land, become 
morasses of sodden and wet ground between great gnarled 
trees and creeper roots. In these little pockets umbrosus 
delights to breed. As also aitkeni among the low hills, but 
not on the flat. 

"In this flat land virgin forest I have never found any 
other species than umbrosus, and among the low hills none 
other than of that type or aitkeni. 

" In the uplands and mountains aitkeni is the common 
species in the pools among the rocky streams and in the 
tributary ravines, occasionally specimens of the umbrosus type, 
but probably not umbrosus (Theobald), are found. 

" It may be recalled that in a paper entitled ' Certain 
Observations in the Epidemiology of Malarial Fever in the 
Malay Peninsula,' which was reported to Government, I said 
that umbrosus does not occur in the hill-land jungle. This 
is, I believe, true, sensu restricto, though some of the rare 



286 ON MOSQUITOES 

anopheles mentioned in that paper as occurring in the hinter- 
land hill jungle belong to that type. 

" As for other species, I have never found any in virgin 
forests. Still I have found barbirostris, asiaticus, and leucosphyrus 
in situations in secondary jungle which would seem to indicate 
that they too might be found in virgin forest. With regard 
to leucosphyrus, if it does occur in the virgin forest on the 
flat land, it must be very rare, and of no importance, because 
Watson, in all his records of flat-land estates, never mentions it. 
At Batu Arang, one day, Dr Watson and I caught fifty umbrosus 
in a few minutes, but in two days did not see a leucosphyrus, 
although we were working along the edge of virgin jungle all 
the time." 

In contrast to these jungle mosquitoes, I may just quote 
Dr Strickland's next paragraph : — 

" Of the common Malay species, fidiginosus, albirostris, 
maculatus, karwari, sinensis, rossii, ludlowi and kochii, I have 
never found one in situations which cause one to suppose they 
would be found in virgin jungle. If ever they do it must be 
so rarely that it does not matter, except as a curiosity." 

Writing of the Peat belts, Dr Strickland says: — 

" I have only found one species of anopheles in the peat 
deposits, namely, umbrosus, and that occurs in some quantity. 
I have examined peat swamps, and drained peat, and peat 
under jungle and peat opened up." 

It will be remembered how a knowledge that A. maculatus 
did not live in peat reduced the amount of land drained by 
pipes on North Hummock Estate, and saved much money. 
(See Chapter XVII.). 

Again, in his paper on " The Mosquitoes of Stream Courses," 
Dr Strickland describes the different kinds of streams and 
rivers to be found, and says : — 

" Small ravine stream under jungle. The stream is usually 
difficult to define ; the whole is rather a streaming morass. 
I have recorded aitke?ii, and species of the umbrosus in such 
places." 

In the table of occurrence rate Dr Strickland gives the 
umbrosus group as only 47 per mille observations on stream 
courses ; but in the record of wells, umbrosus and sinensis head 
the list, both being 241 per mille. 



ON THE MOSQUITOES OF RAVINES 287 

These short extracts will have given some idea of A. 
umbrosus. Called by Mr Theobald umbrosus from its dark 
colour, the name is no less appropriate if we look at its habits 
and haunts. As an adult it frequents the deep shades of the 
forest ; and although, as a larva, it is often found in wells 
of pure water at a hill foot even in sunshine, it most frequently 
lives in stagnant pools of brown peaty water, or in the slowly 
streaming morasses of the virgin jungle. 

It may, however, be found among grass and debris in 
a drain ; but not if there is much current. So it is destroyed 
when a drain is cut through its breeding-place ; as we have 
seen in studying the opening up of the Coastal Plain. Fortunate 
it is that it should be so easily overcome, for with it disappears 
the malaria it carries ; and, as Dr Marshall Barbour says : 
" The evidence obtained in these experiments, both in regard 
to the artificially and naturally infected insects, would confirm 
Watson's conclusion that A. umbrosus is an important carrier 
in Malaya." 

On the Mosquitoes of Ravines. 

In the preceding pages on the Umbrosus group the reader 
will have learned that A. umbrosus is to be found not only 
in the " flat land " or Coastal Plain, but in the low hills 
or Coastal Hills, as I have called them in this volume, 
when these zones are undrained and under jungle. Further 
inland, in the "uplands and mountains," or "inland hills," 
A. umbrosus gives place to a closely allied species, A. 
albotaeniatus var. montanus. 

In the ravines of both of the hill zones, that is of the 
Coastal and the Inland Hills, another mosquito is found. 
In almost every respect save two it is the antithesis of 
A. umbrosus. A. aitkeni, for that is its name, lives in mountain 
streams for preference ; at the edges of the torrent where it 
dashes down the granite mountain-side, the mosquito is found 
often in considerable quantity. Behind roots and rocks, in 
little bays of gravel or sand, it can be caught by one with 
some experience of methods appropriate to stream mosquitoes. 
Whether the speed of the current be great or little does not 
concern it much ; it is found both in crystal streams on the 
steepest parts of our mountains, and in slowly running peaty 
swamps in the Coastal Hills. 



288 ON MOSQUITOES 

But one condition it demands : there must be heavy shade, 
and, for preference, virgin jungle. The shade of a rubber 
estate is not sufficient. Yet shade is not the only condition ; 
for it has never been found in the Coastal Plains even when 
under heavy forest. It is in the strictest sense the stream 
breeder of our hill land when under virgin forest ; and not 
a pool breeder like A. umbrosus. Unlike A. umbrosus it rarely, if 
ever, attacks man ; indeed, it rarely enters a house : nor is it 
like an anopheles in its general appearance, being a little 
brownish-red, hunchbacked, culex-looking insect. A. umbrosus 
is a fierce biter, a strong flier, and lives well in captivity ; 
A. aitkeni is the opposite. While A. umbrosus is an important 
carrier of malaria, A. aitkeni has never been infected experi- 
mentally ; which can be said of few anopheles, even of those 
known to be harmless under natural conditions. 

In two respects it is akin to A. umbrosus: one is its 
presence in virgin jungle ; the other its low place in the 
developmental scale of the anopheles. A. umbrosus is 
covered mainly by hairs ; it has not a ventral tuft of scales, 
like A. barbirostris and some others of the Myzorhynchus group. 
A. aitkeni has still less scale clothing, and has not even a 
patch of colour on its wings. Both belong to the group of 
primitive mosquitoes called by Major Christophers — the Proto- 
anopheles ; and it is not uninteresting that they support his 
theory of their ancient ancestry by being the sole and original 
inhabitants of our virgin jungle ; for A. albotaeniatus var. 
montanus is perhaps an offshoot of the original umbrosus 
stock living in the coastal swamps, which has pushed its way 
up into the ravine swamps in the hills ; at least so I often 
think of it. 

It was the discovery that A. umbrosus did not extend 
beyond the Coastal Hills into the Inland Hills (where only the 
rarer umbrosus types were found), which led Dr Strickland 
to his theory of the Inland Hills being non-malarious as long 
as they were under jungle ; a discovery which I discuss in the 
chapter on " Inland Hills" (XX.). 

When a Ravine is Opened. — Having described the mosquitoes 
of the ravines when under forest, it is now time to consider the 
changes that occur when the jungle is cut down : what happens 
to the original inhabitants ; and what new-comers, if any, 
appear. 




Fig. 94. 
The Vegetation in a Ravine destroyed by Silt, and sunlight admitted. 




Fig. 95. — Silt Pits. 



[To face page 283. 



ON THE MOSQUITOES OF RAVINES 289 

I. If the jungle be felled and burned off, and the bottom 
of the ravine converted from a slowly streaming morass to a 
dry bed intersected by clean weeded drains carrying crystal 
streams sparkling in the sunshine, the conditions are no longer 
suitable for the original inhabitants. A. umbrosus, montanus, 
and aitkeni all disappear : in their place appears the deadly A. 
maculatus, which, alone of all mosquitoes in Malaya, can make 
its home in fast-running streams free from grass and other 
vegetation ; and which, as we saw, is the cause of the per- 
sistence of malaria in the hills (Chapter X.). This mosquito 
is one of the most important carriers of malaria, an observation 
which has been confirmed by Stanton, Strickland, and others ; 
and so readily is it infected artificially that Dr Barbour used it 
as the "control" when experimenting with other species. 

Its liking for streams is shown statistically by Dr Strickland's 
tables. In streams there is, of course, often a deposit of silt ; 
and among the species found in silts, A. maculatus occurs at the 
rate of 522 per mille of the observations ; the next, A. aconitus, 
which requires a grassy edge to the stream, being 175. In 
another table, that of the " Mosquitoes of Stream Courses," 
even although it includes streams of every description, from 
great rivers to streaming ravine morasses, many of which are 
unsuited to the insect, A. maculatus still heads the list with a 
rate of 340 per mille ; while A. barbirostris comes next with 153. 
Commenting on this, Dr Strickland says : " This table shows 
the very marked predominance of maculatus over the other 
species in this respect, and justifies the appellation usually 
given to it of a stream breeder, originated by Watson." 

Had the table been confined to fast-running streams in 
sunshine free from weeds, the position of A. maculatus would 
have been even more predominant ; if indeed, as I believe, it 
would not have been the sole representative of these insects. 

To the power it has of living in such streams is due the 
difficulty of eradicating the malaria of hill land by ordinary 
agricultural "cleanliness"; and the necessity there is for the 
use of "oiling," "subsoil drainage," or some other special 
measure. 

II. When the jungle in a ravine is felled, the timber is not 
always burned off; nor is the ravine always drained. The 
timber may be allowed to rot, and the ravine to remain a 
swamp. Then A. maculatus is no longer the sole and supreme 



290 ON MOSQUITOES 

occupant. In the portions of the ravine where the water is 
clearest and running freest, it will be found. In parts where, 
the water is more stagnant, vegetable decomposition is going 
on under water, on the surface are frothy masses, and bubbles 
rise through the water as one wades in it ; one takes A. 
sinensis, a mosquito much less fastidious than A. maculatus. 
At other spots, where there is little current, may be found such 
mosquitoes as A. barbirostris, A. kochii ; and if the ravine is 
flat and some grass has grown up, it may be A. aconitus and 
A.fuliginosus. A. rossii readily appears if there is any pollution 
from human or animal excrement. 

III. Into such a ravine silt may be washed down from the 
hills. If grass be present, the silt may kill it out, and the 
decomposition of the grass unfits the ravine for A. maculatus, 
but makes it suitable for A. sinensis. On the other hand, silt 
pouring into an unopened ravine may kill out the jungle and 
allow the ingress of A. maculatus. If it is desired to preserve 
the jungle in a ravine, then measures must be taken to prevent 
silt being washed down. The favourite method at present is 
the "silt pit"; but the end can also be achieved in some places 
by growing a belt of grass above the ravine. 

IV. Another condition of great interest, which may occur 
in ravines, is that where the ravine is drained, but weeds, and 
particularly ferns, have almost completely covered the ground. 
In addition to the close shade of the ferns there is the shade 
of rubber or secondary jungle. This is a different condition 
from that of the original ravine when under virgin jungle, 
and is practically harmless from a malarial point of view. 
Owing to the drainage there is no great area suitable for 
A. umbrosus to breed in ; for the drains, even when obstructed 
in parts, are not comparable with the wide morass stretching 
from side to side of the ravine, when undrained and under 
jungle. Nor is it a favourite spot for A. maculatus, since the 
heavy shade of the ferns and trees is inimical to that insect. 
Some may be taken in the more open places, but nothing in 
comparison with the haul got were the ravine clean-weeded 
and without the shade of the ferns and weeds. This condition 
represents a stage in the reversion of the ravine to virgin 
jungle, when it is becoming unfit for A. maculatus, and has not 
yet become extensively suitable for A. umbrosus. 

V. Yet another condition is sometimes found not favourable 




Fig. 96. 
The Drain is almost obliterated. The ground is covered by ferns and secondary 
jungle. This " represents a stage in the reversion of the ravine to virgin jungle, 
when it is becoming unfit for A. maculatus, and has not yet become extensively 
suitable for A. umbrosus." 




Fig. 97. 
Photograph of a recently-drained " Sendayang Swamp." The Sendayang is 
seen to be as high as a man, and forms a dense covering over the swamp. In the 
background is seen the edge of a secondary jungle which is creeping in ultimately 
to cover the Sendayang, so that once again " the jungle comes into its own." 

[ To face page 290. 



THE SILENT WAR 291 

to the spread of malaria. The ravine is free from jungle, is 
swampy and undrained, and covered with " rushes," known 
locally as " sendayang." This may form a complete cover to 
the water of the swamp ; and where the shade is complete, no 
larvse will be taken as a rule ; although occasionally A. sinensis 
will be found. Where, however, the shade is not complete, 
larvae may be found ; the species depending on the quality of 
the water. As vegetable decomposition is the rule, the 
commonest species is A. sinensis ; where the water is a little 
clearer, A. barbirostris, and where clearer still, A. maculatus. 
As the former two are not important carriers of malaria the 
"sendayang" swamp is not specially dangerous; but one must 
beware of the open spaces. Where such a condition occurs on 
an estate and malaria exists, it is safer to drain the swamp and 
oil the drains, than trust to the cultivation of a complete cover 
of " sendayang." 

The Silent War. — Such are a few of the kaleidoscopic views 
of malaria and mosquitoes presented in the different zones 
of this country, and even in one ravine in a single zone. 
Untouched by the hand of man, this is a country covered by 
an evergreen jungle, marked off into zones, some of which 
are malarial, and some non-malarial. When the jungle is 
rudely swept away, man seems to conquer. In reality a 
condition of " unstable equilibrium " has been produced ; or 
rather it can be described more correctly as the beginning 
of a war that can only end in man's defeat, however long it 
may be prolonged : man with knife and axe and fire ; the 
jungle with its myriads of aerial troops. 

Against the intruder, the jungle wages a ceaseless, though 
silent, warfare. It neither sleeps nor slumbers; and if it is to 
be kept in check, it requires of man endless effort. Ever 
vigilant, it sends forward, at every opportunity, its advance 
battalions. Along the drains creep the water-loving grasses 
and rushes ; on their sides soon appear other grasses and tiny 
ferns. Grasses, ferns, wild bananas, and bushes grow on the 
dry ground of the ravines. Gradually leaves, sticks, and silt 
obliterate the drains ; the ravine reverts to its original swamp ; 
the ferns and bushes are replaced by the trees of the original 
forest. The jungle comes into its own. With all these changes, 
the insect life of the ravine changes too : at one period the 

x 



292 ON MOSQUITOES 

insect inhabitant may carry disease ; at another period it may 
be harmless. And one zone differs from another. It is in 
the power of man temporarily to arrest these changes at any 
stage favourable to himself, or to allow them to march to their 
destined end. 

Interesting as these changes are from a scientific point 
of view, no less important are they to the sanitarian. From 
their study we have learned to understand why malaria appears, 
varies in intensity, or disappears ; although at first sight there 
may be little to account for it all. And the knowledge has 
given us power already to advise what should be done, or left 
undone, to control the disease. As we learn more, perhaps the 
time will come when we shall be able to say to one species 
of anopheles, " Come," and to another, "Go," and shall' be able 
to " abolish malaria with great ease, perhaps at hardly any 
expense." 




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[To face page 292. 



CHAPTER XXVI 

THE MALARIA OF KUALA LUMPUR 

Measures taken to bring about its Abatement, showing the Failure of 
Empiricism and the Success of a Scheme based on the Findings of 
Entomological Research. By Dr A. R. Wellington, M.R.C.S., 
L.R.C.P., D.P.H., D.T.M. and H. Cantab., Senior Health Officer, F.M.S. 



Introduction. 

The town of Kuala Lumpur is situated on the Klang River, 
near the centre of the State of Selangor. It is a double capital, 
being the capital of the State and the capital of the Federation, 
and it is the headquarters of both the State Government and 
the Federal Government. 

The whole township has an area of about twenty square 
miles. 

The town is bounded roughly by a circle, having at its 
centre the junction of the Klang 
and Gombak rivers. 

The Klang makes, with the 
Gombak and its tributary the 
Batu, the figure of a Y. which 
divides the town into three ap- 
proximately equal portions. 

The western portion, which is 
the European residential reserve, 
is made up of hills and ravines. 

The northern portion is flat. 

The eastern portion is flat in 
its northern half, hilly in southern half, except for a strip, 
60 chains long and 20 chains wide, by the side of the river. 
This strip constitutes the business area of the town. 

The population which in 1905 was 38,459 is now (1920) 

67,930- 

298 




294 THE MALARIA OF KUALA LUMPUR 

In 1905 most of the European officials were housed on the 
hills in the European residential reserve. The sides of the 
hills were for the most part covered with jungle, and the 
inverts of the valleys were jungle-covered swamps. The 
unofficial Europeans occupied houses on the flat to the east 
of the Klang River. They were isolated houses in their own 
compounds. 

The business area, in which three-fourths of the total 
population resided, was closely built upon. 

Distribution of Malaria previous to 1906. 

Dr Fletcher, in his report dated 30th July 1907, states as 
follows : — 

" Until the end of 1906, malaria among the inmates of 
the European quarters was almost unknown, except in a few 
instances, and in these it could generally be proved that the 
disease had been contracted elsewhere. In those cases in 
which malaria was thus imported it never spread ; no other 
inmates became infected. From this it may reasonably be 
inferred that no mosquitoes were present which were capable 
of carrying the infection. Until September 1906 I had not 
seen a case of malaria in a European house in which the 
probability of infection in another district could be excluded. 
Dr Travers, whose experience in Kuala Lumpur extends over 
a period of twelve years, states that until this year he had 
not seen malaria among the European women and children 
of Kuala Lumpur, though cases have occurred among the men 
whose duties take them outside the town. 

Malaria is endemic amongst that portion of the population 
which resides along the banks of the river, or near the swamps 
which border it. 

Since 1903 the blood of all patients suffering from fever 
has, when practicable, been examined. Any figures, therefore, 
quoted hereafter refer only to cases which have been proved 
to be malarial by the demonstration of the parasite. During 
1906 malaria parasites were found in sixty-six cases from 
Kuala Lumpur. Nearly all the cases seen came from the 
endemic area, only three occurring in European houses, and 
these during the last quarter of the year." 

Dr M'Closky, who had had twelve years' experience of 
Kuala Lumpur, stated in August 1907 : " I saw my first case 
of malaria in a European, contracted in Kuala Lumpur, only 
last month." 



OUTBREAK OF MALARIA IN HILL LAND 295 

There can be no doubt that up till 1906 malaria was 
confined to the areas which bordered on the river, and the 
hills were free. 



Outbreak of Malaria in the Hill Land, West of River. 

Early in 1906 the jungle-covered swamp at the foot of 
Federal Hill was cleared, and an attempt made to dry the 
area by means of earth drains. The clearing was done by the 
Public Works Department, in order to improve the amenities 
of the locality prior to the erection of buildings on the high 
ground adjacent. About the same time Dr Fletcher had the 
blukar and scrub cleared from the swampy valley below the 
General Hospital. This was done to improve the appearance 
of the place, and to allow for better drainage. 

During the year the hospitals in Kuala Lumpur received 
many bad cases of malaria from the hill estates which were 
being started in the neighbourhood. The danger of opening 
up land had long been known to the pioneers of the country 
who attributed the high malaria incidence and death rate to 
some miasma set free by disturbance of the soil. 

Towards the end of the year cases of malaria began to 
occur in Kuala Lumpur among the Europeans occupying the 
bungalows near the clearings, and among the patients and 
servants in the hospital. Previously both areas had been 
healthy. The incidence increased, and by the end of 1907 
all the houses on Federal Hill and Carcosa Hill had cases 
of infection. Cases had also occurred in most of the houses 
near the hospital. The Police Barracks which were on the hill 
opposite the hospital had many cases. 

Dr Fletcher, in July 1907, sent in a report describing the 
outbreak. By means of a spot map he showed that the cases 
were coming from the neighbourhood of the clearings. He 
said : — 

"The two main districts affected by the disease are — {a) 
Those parts near the swamps at the foot of Federal Hill ; 
{b) the General Hospital and surroundings. 

"The cause of this outbreak must be some condition favour- 
able to the breeding of the mosquitoes which convey the 
infection. 

" In each of the two neighbourhoods, the Federal Hill and 
the General Hospital, there is some low-lying swampy ground. 



296 



THE MALARIA OF KUALA LUMPUR 



A couple of years ago these swamps were not drained, and in 
wet weather there was a considerable depth of water, but at 
that time there was no malaria in either neighbourhood. 

"About one and a half years ago these swamps were 
drained, and subsequently malaria appeared in the houses 
near. The drains which were made are very irregular, and in 
places there are small pools and miniature dams which probably 
make ideal breeding-places for the noxious mosquitoes. 

"The remedy for the outbreak is efficient drainage. On 
that subject I am not qualified to advise, but would venture to 
suggest that the matter be laid before the Health Officer. 

" The following figures show the actual numbers of the cases 
from the various districts which have come under my personal 
notice, and I would point out that they are, therefore, merely 
an indication of the distribution of malaria in Kuala Lumpur, 
and not the actual number of cases which have occurred. To 
obtain the latter, the figures given below would need to be 
multiplied by a factor, in most cases as large as 10, and in 
some, such as the Police Depot, not larger than 1-50." 





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January 
February . 
March 
April . 
May . 
June . 

Total . 


5 

2 
1 

3 
6 


1 
1 
1 

2 
3 


1 
2 
1 


1 


5 
4 
3 

4 
4 


5 
2 
2 

3 

5 

2 


1 
1 


1 
5 


6 
8 
3 

4 




3 
1 
1 
3 
3 


A 

4 
2 

3 
5 
2 


22 
23 
20 
12 
25 
3° 


17 


8 


5 


21 


19 


8 


= 5 


11 


18 


132 



Dr M'Closky, the Acting State Surgeon, in forwarding the 
report to Government, wrote : — 

" Dr Fletcher rightly attributes this increase of malaria to 
some condition favourable to the breeding of mosquitoes which 
convey the infection, but I think there is another factor to be 
considered, viz., the source of infection of mosquitoes. This 
has multiplied considerably by the large increase of malarial 
patients admitted to the General Hospital from the different 
estates." 

The matter was referred to the Health Officer, Dr Thornley, 
who wrote : — 




{To Jam page 290. 



THE MALARIAL COMMITTEE 297 

" The method of draining valleys below Federal Hill is far 
from satisfactory, if not entirely wrong, as far as the attainment 
of the object of preventing breeding-grounds for mosquitoes 
is concerned. The herring-bone system adopted leaves the 
ground between dry, but the drains themselves are grand 
breeding-places. The drains below the European Hospital 
are lined with stones, and these result in the formation of 
small pools. The drains should be on the lines of Klang. 
Without money for upkeep it is a case of throwing money 
into swamps." 

At Klang, Malcolm Watson used contour hill-foot drains 
to intercept the water from the hills. 

The Malarial Committee, its Investigations, Discoveries, and 
Recommendations. 

In September 1907, the British Resident appointed a com- 
mittee for the purpose of (a) examining the area complained 
of; (b) inquiring into the results arising from the present 
condition ; (c) advising as to the methods to be employed 
for the improvement of each area, and to make an estimate 
of the cost in each case. The members of the Committee were 
— the Chairman of the Sanitary Board, Mr E. S. Hose ; the 
Health Officer, Dr Thornley; the Medical Officer, Dr Fletcher; 
and the Executive Engineer, Mr J. E. Jackson. 

The Committee started work by asking for the services 
of the Government Entomologist, Mr C. H. Pratt, to make 
a thorough investigation into the areas complained of, for the 
purpose of ascertaining (a) the actual existence of malarial 
mosquitoes in the quarters infected, (d) the proportionate 
extent to which each area actually constitutes a breeding- 
ground, for such mosquitoes. 

The entomologist, during his investigations, discovered 
larvae of anopheles " present in the streams flowing through 
the cleared portion of the valleys, but not in those parts where 
the streams remained covered with a thick growth of bushes. 
Even in the open portion anopheles were not found where 
the stream flows swiftly between even banks, but wherever it 
had been scoured by flood and the stream had broadened out 
with retarded flow at the sides, there anopheline larvae were 
present in large numbers." 

Fletcher, who confirmed Pratt's discovery, was quick to 



298 THE MALARIA OF KUALA LUMPUR 

recognise the importance of it, and in his letter to the 
Chairman he stated : " These facts demonstrate the great 
danger of clearing jungle, unless it is possible at the same 
time to convert these streams into regular channels with 
clearly-cut sides, preferably of cement or brick." 

The Executive Engineer, Mr J. E. Jackson, prepared 
surveys and estimates for a system of drainage in the areas 
referred to. The plans showed open brick drains running 
through the centre of the valleys, and subsidiary rubble drains 
covered with turf discharging into them. 

In February 1908 the Committee sent in a detailed report. 

The following extract from Para. 2 shows the importance 
they attached to Pratt and Fletcher's discovery : — 

" It is very noteworthy that anopheles were found to be 
most prevalent in sluggish streams or earth drains where the 
thick overhanging undergrowth had been cleared away, as 
is the case, for instance, in the valleys on both sides of 
Hospital Road below the General Hospital, and at the foot of 
Federal Hill, and in the low-lying land in the angle between 
Brickfields Road and Damansara Road. These facts demon- 
strate the great danger of clearing the jungle covering of 
streams unless it is possible at the same time to convert such 
streams into regular channels of a uniform and fairly steep 
gradient, with clearly-cut sides. The Committee do not, how- 
ever, wish to underrate the value of clearing jungle, provided 
that efficient drainage is undertaken at the same time." 

Plans of Mr Jackson's drains, viz., open brick and subsoil 
rubble, were put up. $27,585 were asked for. 

In asking for upkeep, the Committee said, " We consider 
that it will be necessary to maintain an upkeep gang of ten 
men who should be constantly employed in keeping these 
drains free from obstruction and in good order after they 
have been made, and with this end in view we recommend 
an annual expenditure of $1500, to which should be added 
a further sum of $500 for current repairs to drains." 

Criticism of Committee's Findings. 

The findings of the Committee came in for a good deal 
of criticism. 

Pratt and Fletcher's discovery and deductions drawn from 
it were so incompatible with the generally accepted ideas, 




[To }oxe pagt 2S)8. 



CRITICISM OF COMMITTEE'S FINDINGS 



299 



and so contrary to the teaching of the day, that little credence 
was given to them. 

In every country where mosquito control had been attempted, 
emphasis was laid on the importance of clearing up all scrub, 
undergrowth, and jungle near to habitations and in towns. 
Local medical men had always advocated similar measures. 

Drains Recommended by the Committee. 





Medium Open Concrete Drain. 

Covered with turf 



Y 




/?«66/e filling 



+9 inS.- 
Subsoil Rubble Drain. 

In Klang and Port Swettenham jungle clearing had been 
used with success, and to most there seemed to be no reason 
why the opposite should be the case in Kuala Lumpur. 

That anopheles carried malaria was known to all the 
local medical men, but the fact that there were a dozen or 
more species of anophelines in Malaya, and that some were 
carriers and others were not, was known to two or three 
only, and their knowledge of the subject was very limited. 



300 THE MALARIA OF KUALA LUMPUR 

Practically nothing was known of the life-history of the 
different species, and it was not realised that conditions favour- 
able for one might be unfavourable for another. 

The anopheline which did the harm at Klang and Port 
Swettenham was A. umbrosus, a. jungle breeder on flat lands; 
that which did the harm in Kuala Lumpur was A. maculatus* 
which breeds in the open on hilly lands. 

In due time the report was submitted to the High 
Commissioner for his consideration. The High Commissioner, 
who paid a visit of inspection to the areas in question, was 
not convinced that the clearing had had any connection with 
the outbreak. He pointed out that there were cleared valleys 
of a similar nature in Singapore, and that they were free 
from malaria. He disallowed certain of the open brick or 
concrete drains and substituted rubble drains. 

The sum asked for by the Committee was $27,585, the 
sum sanctioned was $10,320. Nothing was allowed for upkeep. 

First Attempt on part of Public Works Department 
to exterminate Malaria by Drainage. 

The European residential area was on State land, and the 
task of ridding it of anopheline breeding-grounds was entrusted 
to the State P.W.D. to carry out in 1908. 

It does not seem to have been realised that the problem 
was chiefly an entomological one, and that the engineering 
works necessary were only a means to an entomological end. 
The end aimed at was the rendering of certain areas impossible 
for mosquito propagation, and no system of drainage, however 
satisfactory, from an engineering point of view, was of the 
slightest use if that end were not attained. 

Also it seems to have been forgotten that the extermination 
of any animal from an area where it is prevalent is rarely 
possible, unless the exterminators possess some knowledge of 
the animal and its habits, and that the chances of success are 
infinitesimal when the hunter cannot recognise the animal 
when he sees it. 

Mosquitoes are animals, and the above applies to anti- 
mosquito schemes. 

With only one-third of the sum deemed necessary by the 
Committee the Public Works Department had no chance of 
* A. maculatus was then called A. (JVys) willmori. 



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INVESTIGATIONS BY THE HEALTH OFFICER 301 

success even had they gone to work in the best possible way. 
They did not, however, attack the problem in the proper 
manner, and it is probable that, had the full sum been voted, 
the result would still have been a failure. 

The engineers had never made a study of mosquitoes, 
and they could not spot an anopheline larva when they saw 
one. Being unfamiliar with the appearance of the larvae, they 
were unable to find out for themselves which were the dangerous 
areas and which were not. They could not tell, therefore, 
where to begin. The index of success was the absence of 
larvae from areas which, before treatment, contained them. 
They could not check their results, and they therefore did 
not know where to end. 

As they knew nothing of the mosquitoes they wanted to 
get rid of, it was clearly a case for co-operation with those 
who did know. Co-operation was not invited. 

In direct opposition to the recommendations of the Com- 
mittee, the valleys were cleared without being efficiently drained. 

Dr Thornley had advocated drainage on the Klang system, 
that is to say contour hill- foot drains, to intercept the water 
before it got to the swamps. His advice was not followed, 
and straight tap drains were put in instead. These drains 
only dried the ground within a few feet of them ; the inter- 
vening spaces remained wet. 

The subsoil rubble drains recommended by the Committee 
were not put in, open rubble drains were used instead. These 
soon became choked with silt. 

When all the money had been expended, the valleys were 
only half done. 

No provision having been allowed for upkeep, the drains 
when finished were left to take care of themselves. 

Investigations by the Health Officer, and his Findings. 

In the middle of 1909, malaria in the European quarter 
was as bad as ever, if not worse, and it was evident that the 
measures taken had not been successful. 

In an endeavour to arrive at the cause of failure, the writer 
who had succeeded Dr Thornley as Health Officer made a 
personal survey of every valley in Kuala Lumpur from top 
to bottom, through cleared portions as well as through those 
still covered by jungle. 



302 THE MALARIA OF KUALA LUMPUR 

Every stream, pool, or collection of water met with was 
searched for anopheline larvae. Those caught were bred out 
and identified. 

No larvae were found in the jungle-covered portions of the 
valleys, though water was plentiful and careful search was made. 
In the cleared portions they were easily found. There were 
many cases where larvae were plentiful right up to the edge of 
a clearing, but absent from the jungle-covered pools a few feet 
away. Pratt and Fletcher's observations were thus confirmed. 

In the valleys which had been treated by the Public Works 
Department, larvae were plentiful. They were particularly 
numerous in the spring water which trickled over the surface 
of the rubble drains. Not having been covered with turf (as 
recommended by the Committee), or otherwise protected, the 
spaces between the stones had become blocked by mud and 
silt, and the water which should have percolated through the 
rubble flowed over the top. 

In some valleys where concrete drains had been constructed, 
the only place where one could walk dry-shod was the top of 
the drain itself; everywhere else was like a sponge, and among 
the thousands of pools existing it was not difficult to find larvae. 

A. maciilatus and A. karwari were the species most 
common in the spring water which oozed from the bases of 
the hills. The smaller the pool the more likely it was to 
contain larvae ; even the scrapings from the surface of wet sand 
showed them. Running spring water contained them. 

A. rossii* and A. kochi were found in dirty water such as is 
contained in buffalo wallows, wheel tracks, and drains con- 
taminated by sewage. 

A. barbirostris and A. sinensis were met with at the edges 
of larger pools and ponds, especially where those edges were 
grassy or grass appeared above the surface. They were also 
found among floating debris. 

A. umbrosus larvae were not met with. 

After the valleys had been done the flats were searched. 

A report accompanied by a spot map was submitted to 
the Principal Medical Officer. On the map fifty Anopheline 
breeding-places were shown. Attention was drawn to the fact 
that water in cleared valleys harboured anopheline larvae, while 
water in jungle-covered valleys did not. 

* A. rossii now called A. vagus. 




[To face pag' 302,. 



INVESTIGATIONS BY THE HEALTH OFFICER 303 

Malcolm Watson had demonstrated that A. umbrosus and 
maculatus were carriers ; nothing was known concerning the 
carrying properties of the other species. Watson had also 
shown that umbrosus is a jungle breeder, and that it disappears 
in clearing. 

The cause of the fever could not be A. umbrosus, for that 
species was conspicuous by its absence ; besides, the clearing 
of jungle would have lessened the amount of malaria, whereas 
it seemed certain that it had had the opposite effect. 

A. maculatus, the only other carrier known, was found 
breeding freely in the open valleys but not in those covered 
by jungle. The houses close to jungle-covered valleys had no 
fever, those near cleared valleys had. The obvious inference 
was that the clearing of the valleys had created conditions 
favourable for the propagation of maculatus, that the maculatus 
population had therefore increased, and the increased number 
of carriers had raised the incidence rate among those living in 
the neighbourhood. 

Pratt and Fletcher's theory was correct, and the warning 
issued by the Committee was sound. 

In the execution of the anti-mosquito works, that warning 
had been ignored. The valleys were felled and cleared but 
not efficiently drained, and an increase instead of a decrease 
in the number of breeding-places resulted. 

The following is an extract from the Health Officer's annual 
report of 1910 : — 

" It was noted that where the valleys had been cleared of 
jungle and blukar, larvae of the malaria-carrying anopheline 
{A. maculatus) were found without difficulty in the clear water 
which had issued from the springs at the hill-foot. In the 
valleys covered by blukar or jungle, where the water (of which 
there was plenty) was coloured with vegetable matter, not a 
single anopheline larva was found. This experience agrees 
with that of Pratt and Fletcher in 1907. As malaria-carrying 
anophelines breed in cleared valleys and shun those covered 
with blukar, the obvious inference is that the clearing of valleys 
will be followed by an outbreak of malaria if foci of infection be 
present and the valleys are left inefficiently drained." 

The findings of the Health Officer were not generally 
accepted, and even the medical officers remained unconvinced 
of the danger of clearing valleys. 



304 



THE MALARIA OF KUALA LUMPUR 



The subject was so important that independent action should 
have been taken to prove or disprove the theory, but nothing 
was done. 

Experimental Drainage Works on Petaling Hill. 

The investigations of the Health Officer commenced about 
the middle of 1909, and the report on the anopheline survey 
was delivered to the Principal Medical Officer in April 1910. 

During the interval notifications of malaria were constantly 
being received. Each case was gone into as thoroughly as time 
permitted. At the end of 1909 a European who lived on 
Petaling Hill, a new residential area not included in the 
Committee's report, wrote in complaining that all his house- 
hold had been down with fever, for which he blamed the 
ravines in front of his quarters in Belfield Road. The ravines 
contained scrub and blukar, but there were open spaces in 
them. The inverts were wet and swampy (Fig. 99). An 
anopheline survey by the Health Officer showed the presence 
of the fever-carriers A. maculatus in the open areas. The 
findings were reported to Government and drainage recom- 
mended, a concrete drain to run down the centre, and contour 

open earth-drains at bottom of slopes 
to connect at intervals with centre 
drain. 

The State Engineer fixed upon 
one of these valleys as a suitable 
place for experimentation in drainage, 
and trials were begun. 

The valley was cleared of scrub, 
and drainage on the herring-bone 
system tried. The central drain was 
an earth channel, having at its invert 
concrete half-pipes roofed with flat, perforated, concrete slabs ; 
the rest of the channel was filled with broken stone. Except 
that the pipes were different, the drains were similar to those 
used with success at Panama. 

The subsidiary drains or ribs of the herring-bone were earth 
channels filled with broken stone (Fig. 100). 

The experiment was watched by the Health Officer, who 
checked the results by frequent mosquito surveys. 

The concrete pipes worked well. The rubble drain when 





Fig. 103. — Petaling Hill, Kuala Lumpur. 

A general view of the ravine, with the central concrete and rubble drains ; some 
subsidiary rubble lateral drains ; in the distance some subsoil clay pipes being laid in 
a contour drain and on the land ready to be laid. 

[7\> face pige 304. 



INVESTIGATIONS OF THE HEALTH OFFICER 305 

new dried the soil for a couple of feet on either side ; beyond 
that they had no influence, and the ground remained wet and 
sloppy, and in the small pools larvae continued to develop. 
In a short time the interstices of the rubble drains became 
choked with mud and silt, and the drains ceased to convey 
water. The choked drains were taken up and relaid. To dry 
the spaces between some contour or intercepting drains were 
constructed at the hill-foot. The contour arrangement was a 
great improvement on the simple herring-bone, and for a time 
the valley was dry. In a month, however, the rubble drains 
had again become choked, and it was decided to abandon 
them. 

In February 1910, Dr Malcolm Watson, at a meeting of 
the British Medical Association in Kuala Lumpur, read an 
interesting paper on malaria prevention. He described what 
had been done in Malaya and the results. He pointed out the 
difficulties he had encountered in hill lands, and he advocated 
a system of contour hill-foot drainage by means of clay pipes 
laid underground. At that time clay pipes were not to be 
had in Malaya. The local potters made flower-pots and jars, 
but they had never tried their hands at pipes. Dr Watson 
pointed out that there was no reason why these pipes could 
not be turned out very cheaply, and he showed specimens 
which he had had made locally. He described a system of 
clay-pipe drainage, which he proposed to use on certain hill 
estates in the highly malarious Batu Tiga district. 

In July, Dr Watson paid a visit to the experimental drain 
at Petaling Hill, and offered some friendly criticism. He 
considered that the main drain, the concrete pipe overlaid 
with stone, was performing its task satisfactorily, but that it 
was unnecessarily expensive. The rubble drains he condemned. 
A trial of clay pipes was recommended, and as none could 
be obtained in Kuala Lumpur he offered to provide a pattern 
which the local potters could copy. Mr R. D. Jackson, who 
had newly taken over the anti-malarial drainage of State 
lands in Kuala Lumpur, took action on the lines suggested 
and arranged for pipes to be made. The potters, seeing there 
was money in it, commenced making pipes on their own. 
This was the beginning of an industry which has so developed 
that there are now half a dozen potteries which manufacture 
clay pipes for anti-malarial purposes. 



306 THE MALARIA OF KUALA LUMPUR 

The rubble drains were all taken up and replaced by clay 
pipes overlaid with broken stone, a system similar to that 
which had proved successful in Panama (Fig. 101). The valley 
was dried, and remained dry for a year or more. Upkeep 
was necessary. 

Second Attempt by Public Works Department to exterminate 
Malaria by Drainage. 

Somewhere about the middle of the year 1910, a sum 
was voted for the purpose of remedying the defects of the 
1908 drainage system, and for certain extensions. The work 
was again entrusted to the Public Works Department to carry 
out. On this occasion both Federal and State lands were 
concerned. Operations on Federal land were allotted to a 
Federal engineer, that on State land to a State engineer. The 
two worked independently. 

Plans for the State land were submitted to the Health 
Officer, who passed them on condition that they were not to 
be considered final, but that any deviation found necessary 
during the progress of the work would be carried out. The 
Health Officer asked for the drainage of jungle-covered valleys 
and the felling to proceed side by side. This was rejected as 
impracticable. 

Plans for the Federal land were not submitted. 

Work on State land commenced in July. The writer made 
frequent mosquito surveys during the progress of the work, and 
communicated the results to the Executive Engineer. 

Contour drainage had been repeatedly advocated by the 
writer, but up to this time no engineer had consented to give 
it a trial. In this month a trial on a small scale was made, 
both in Belfield Road experimental area and in Club Road 
Valley (Fig. 106). An entry in the Health Officer's diary, dated 
28th July, says : " Inspected Belfield Road and Club Road. I am 
glad to see the P.W.D. are trying contour drains at last, though 
they are not making them deep enough." That they were only 
half convinced is shown by the following extract from the same 
diary : " Inspected anti-malarial drains in Club Road. The 
P.W.D. are putting in straight drains where they ought to 
put in contour drains. The scheme will be a failure unless 
the P.W.D. use common sense." Common sense eventually 
prevailed, for the diary entry of 28th September says : 




Fig. 104.— Ci.ub Valley Road, Kuala Lumtur. 
The original condition. 




Fig. 105.— Club Valley Road, Kuala Lumpur. 
The Pond at the foot "did not furnish carriers." 



[To face page 306. 



FORMATION OF HEALTH BRANCH 307 

" Inspected Club Road Valley. The contour drains have done 
the trick and the valley is perfectly dry." Leaving out the 
experimental one in Belfield Road, this is the first instance 
of a valley having been drained to the satisfaction of the 
Health Officer. 

Other valleys received attention but the work there was 
not so thorough, and when operations ceased there still 
remained sufficient breeding-grounds to supply all the carriers 
necessary for maintaining the high malarial rate existing in 
the neighbourhood. Much good work had been done, but 
it had not gone far enough. 

While the State authorities were engaged with the works 
on State land a Federal engineer was dealing with the 
Federal area. The Health Officer offered advice but it was 
not taken. Watch was kept, and the various collections of 
water were frequently examined for the presence of larvae. 

The concrete blocks intended for the open drains were 
cast on the spot. Unfortunately, the ground chosen for the 
casting operations was wet and spongy, and many small pools 
formed. The pools became populated with A. maculatus larvae. 
At the end of 1910 so much breeding was going on that an 
increase of malaria seemed inevitable. Warning was given, 
but no action was taken and the breeding continued. 

Formation of Health Branch of the Medical Department. 

In January 191 1 the Health Branch of the Medical 
Department came into existence, and the writer was transferred 
to Taiping in the State of Perak as Health Officer, Perak 
North. 

Taiping is situated on the flat at the base of the hills. 
The European quarter is on that side of the town next to 
the hills. Until the previous year this quarter had been 
healthy, but it was now malarious. The malaria followed the 
clearing of the hill land for rubber growing. Investigations 
were made, and it was found that, as in Kuala Lumpur, the 
carriers were coming from the cleared valleys. All the valleys 
were searched. In those covered with jungle no larvae were 
found; in those which had been cleared A. maculatus breeding- 
grounds were found in plenty. A mosquito survey of the 
whole town was made, and a spot map prepared. Only near 
the bases of the hills were carriers found. The European 

Y 



308 THE MALARIA OF KUALA LUMPUR 

area suffered, but there was little malaria in the rest of the 
town. 

Malarious hill estates in the neighbourhood were investigated, 
and in each case A. maculatus breeding-grounds were found in 
the cleared valleys and not in the jungle-covered ones. Pratt 
and Fletcher's theory was true for the hill lands of Perak. 

Continuance of Malaria in Kuala Lumpur. 

Malaria in Kuala Lumpur in 191 1, instead of declining, 
increased. 

The conditions of the valleys at the beginning of the 
year were as follows. 

Club Road Valley was dry except at its mouth, where there 
was a large pond (Fig. 105). The pond did not furnish carriers, 
and it therefore had no influence on the malaria. 

Bluff Road Valley and Hospital Valley had not been 
completely dried, and there were still maculatus breeding- 
grounds, especially in the upper reaches. 

Venning Road Valley was not satisfactory, and breeding- 
grounds existed. 

In the gardens there were still many dangerous places. 

A. maculatus larvae were easily found near the Federal Anti- 
mosquito Works. 

In fairness to the engineers it must be stated that the 
valleys which had been treated were not the only ones which 
contained anopheline breeding-grounds. 

Owing to the general disbelief in the danger of clearing 
valleys, no action had been taken to prevent further clearing. 

New valleys had been cleared by the Agricultural Depart- 
ment and by others and new breeding-grounds had been 
created. These furnished their share of mosquitoes. 

Every house on Carcosa Hill and Federal Hill had cases. 
All were within easy flying distance of the Federal Anti- 
mosquito Works. 

Confirmation of Watson's Discovery that Maculatus is a Carrier. 

On June the 8th Dr Stanton, the Government Bacteriologist, 
demonstrated the presence of zygotes in the stomach wall 
of A. maculatus taken in a house in Brickfields Road, close 
to the Federal Anti-mosquito Works. On June the 28th, 






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FORMATION OF MALARIA ADVISORY BOARD 309 

in conjunction with Dr Watson, specimens of this mosquito 
were taken in coolie lines on a hilly estate in the notoriously 
malarious Batu Tiga district and sporozoites were demonstrated 
in the salivary glands. Watson's discovery, made in 1906, 
that A. maculatus is a carrier in nature, was thus confirmed. 
Dr Stanton says : — 

" The number of A. maculatus taken in the lines and the 
readiness with which parasites were demonstrated in them 
at a time when I was informed the estate was comparatively 
free of malaria, and the absence of parasites in other species 
of anophelines examined, show the great importance of this 
mosquito in malaria transmission in hill areas." 

It is a pity that Pratt and Fletcher's theory was not tested 
at this stage. The question, however, was not taken up, and 
the theory remained discredited until 191 5 when Strickland 
published a paper confirming it. 

Clearing went on steadily in Kuala Lumpur. 

An extract from Dr Gerrard's health report of 191 1 says : — 

" During the year much jungle and undergrowth was cleared, 
and many subsoil drains laid. In spite of this malaria has 
increased." 

A further extract from the same report is of interest : — 

" The anophelines of the environs of Kuala Lumpur are 
being worked out by Dr Stanton of the Institute of Medical 
Research, and maps showing where larvae are found are nearing 
completion." 

The fact that there was a recent anopheline survey map 
cf Kuala Lumpur already in existence seems to have been 
overlooked, at any rate no use was made of it. 

Formation of Malaria Advisory Board. 

Dr Charles Lane Sansom was appointed Principal Medical 
Officer, F.M.S., in January 191 1. 

On his arrival he found that the medical problem which 
most required attention was malaria and its prevention. The 
position in Kuala Lumpur was far from satisfactory. The 
subject had been engaging the attention of the authorities for 
four years, yet in spite of the efforts made, malaria was on 
the increase. Dr Sansom made investigations and came to 
the conclusion that the reasons for failure to reduce malaria 



310 THE MALARIA OF KUALA LUMPUR 

lay in division of responsibility, lack of thoroughness, and 
unsuitable methods resulting in bad drainage. The works 
had been controlled by various State and Federal authorities, 
each of whom proceeded independently. 

In August Dr Sansom wrote in to Government and pointed 
out " that the suppression of malaria in these States is not such 
a simple matter as it is described in the works of Ross and 
Boyce.'' Because of the difficulties which had to be overcome 
he recommended the appointment of a standing Committee 
to— 

(a) Collect information and evidence with regard to the 

incidence of malaria. 

(b) Select the most appropriate schemes which could be 

used in various parts of the States, and advise 
Government as to how they should be carried into 
effect. 

(c) Issue instructions as to details, control, and upkeep of 

anti-malarial works. 

(d) Diffuse information. 

(e) Undertake any other duties which in the opinion 
of the Chief Secretary would be likely to prevent 
malaria. 

The Committee recommended was — 

The Principal Medical Officer. 

Dr Stanton, " to keep members in touch with research work 

here and elsewhere." 
Dr Malcolm Watson " as the medical representative who 

had had much practical experience." 
One or two prominent planters. 
A district officer who had had experience in Sanitary 

Board work. 
An engineer skilled in drainage work. 

" Such a Committee would inspire public confidence in 
the first place and therefore there would be less resistance 
to any measures which might have to be enforced. The 
Government would be advised as to the best means which 
could be adopted to control the disease, and if all contem- 
plated schemes are submitted to the Committee not only would 
uniformity result but expenditure on useless fads and theories 
be prevented." 



FORMATION OF MALARIA ADVISORY BOARD 311 

Government accepted the recommendations and the Malaria 
Advisory Board was formed. 

The composition of the Board was — E. L. Brockman, Esq., 
C.M.G., Chief Secretary, President ; Dr C. L. Sansom, Principal 




Medical Officer, Vice-President ; J. H. M. Robson, Esq. ; Dr 
Malcolm Watson ; H. R. Quartley, Esq. ; Dr A. T Stanton ; 
F. D. Evans, Esq., Assistant Engineer, Public Works De- 
partment. 

The Board met for the first time in November and there 
was a second meeting in December. 



312 THE MALARIA OF KUALA LUMPUR 

It was decided that the drainage of the European residential 
area should be completed under the instruction of the Board 
"to serve as an illustration of what could be done by this means 
to free an area of malaria." 

It was decided to work on the following lines : — 

(i) All ravines to be cleared for 6 feet up the hill. 

(2) Open earth channels to drain land previous to pipe 

laying. 

(3) Subsoil contour pipe drains (clay pipes) to be placed at 

the foot of all slopes. 

(4) The cement drains already in position to be left for the 

time as they might prove satisfactory. 

(5) Mr F. D. Evans to supervise the work. 

Work commences under Malaria Advisory Board. 

Mr Evans, who was seconded from the Public Works 
Department and appointed Executive Engineer to the Board, 
realising the vital importance of the mosquito side of the 
problem, early took up the study of the local anophelines. 
He was the first engineer in the F.M.S. who had ever bothered 
about them. He was thus able to check results and ensure 
that each section had been freed from breeding-grounds before 
another was commenced. 

Some idea of the incompleteness of previous works can be 
got from the minutes of the Board of 12th February 1912 : 
" The Board is informed that every ravine head is left 
unfinished, thus creating typical mosquito breeding-places for 
mosquitoes most dangerous to health. Additional drainage 
on Petaling Hill is approved. Undergrowth along drains in 
Federal Reserve to be cleared, and when drainage has been 
completed, jungle on both sides of the hill to be cleared. 
Additional work required in ravines between Club Road and 
Maxwell Road." 

To subsoil the whole of the ravines west of the river was a 
big job, something like 50 miles of piping being necessary. 
The work was pushed on rapidly, but of course it took time 
to complete. 

Experiments were made in draining, and it was early found 
that the rubble filling over pipes was not only unnecessary but 
harmful — better results could be got by protecting the pipes 



EUROPEAN RESIDENTIAL AREA CLEARED 313 

from silt with a layer of dried palm leaves and covering in the 
trench with earth. The same system had been used with 
success on Seafield Estate, which had been drained under the 
supervision of Dr Watson. 

The subsoil drains laid in the 1910 campaign were left until 
they showed signs of blockage, when they were taken up and 
replaced by others. By the end of 191 3 there were practically 
none of the old type left. 

European Residential Area cleared of Malaria. 

The results of the drainage was most satisfactory, and in 
191 3 the European residential area for the first time in seven 
years was free from malaria, and it has remained free ever 
since. 

For the first time in the history of Kuala Lumpur, anti- 
mosquito works had been carried out under the authority of 
a Board containing medical entomologists familiar with the 
mosquito it was desired to get rid of. 

The success was due to the complete eradication of 
A. maculatus breeding-grounds, brought about by a system of 
drainage specially designed to deal with the problem. Particular 
mention must be made of the excellent work done by Mr 
F. D. Evans, the Board's executive engineer. He was keenly 
interested in the subject, and he carried out the details of the 
scheme with such thoroughness and skill that no place was 
left suitable for A. maculatus to breed in. Strict attention to 
detail was absolutely essential, for with so efficient a carrier 
as A. maculatus, even small and insignificant-looking pools of 
water are sufficient to keep the disease smouldering. 

Malaria not being a notifiable disease, the incidence figures 
are not available. Europeans, however, are never slow in 
complaining to the Health Officer when a case occurs in their 
households, and the fact that complaints which had been of 
almost daily occurrence in 1910 and 191 1 ceased to be received 
after 191 2 shows that malaria in the European residential 
area came to an end about that time. 

Influence of Drainage not confined to Residential Area. 

The influence of the drainage operation was not confined 
to the European quarter; the shop house area of the town 



314 



THE MALARIA OF KUALA LUMPUR 



was within flying distance, and there is no doubt that it 
benefited. The malaria death rate for the whole town dropped 
from 9-87 in 191 1 to 5-53 in 1912. 

The report of the Health Officer (A. R. Wellington) for 
191 3 says : — 

" The great drop in the death rate for this disease must 
be attributed to the extensive drainage operations which were 
undertaken by the Malaria Advisory Board to get rid of the 
breeding-places of malaria-carrying mosquitoes. Valleys which 
were teeming with maculatus larva; are now bone-dry." 

The action taken by the Malaria Advisory Board in the 
area selected for demonstration purposes had been so successful 
that it was decided to extend operations and deal with other 
areas in the town where malaria was prevalent. 

The following table shows the numbers of deaths among 
the residential population due to " fevers," in most cases 
malarial, the fever death rate per mille population, and the 
general death rate : — 



Year. 


Population. 


Number of 

Deaths from 

Fever. 


Fever 
Death Rate. 


General 
Death liate. 


1907 


41,331 


537 


2-99 


36-40 


1908 


42,775 


423 


9.88 


41-19 


1909 


43,209 


34i 


7-89 


32-95 


1910 


45,642 


486 


10-64 


33-15 


1911 


47,076 


465 


9.87 


39-02 


1912 


48,508 


266 


5-53 


37-oo 


1913 


56,487 


314 


5-56 


35-62 


1914 


58,107 


361 


6-21 


35-88 


1915 


59,727 


325 


5-44 


27-83 


1916 


6l,443 


408 


6-64 


27-73 


1917 


63,064 


293 


4-65 


28-45 


1918 


64,686 


393 


608 


38-34 


1919 


66,308* 


3" 


4.69 


26-36 



* The census in 1921 shows the population to be 70,000. 

The figures for the year previous to 1907 are too unreliable 
to be quoted, for, until that year, the importance of distinguish- 
ing between deaths due to diseases contracted in the town 
and those contracted outside was not generally realised, and 
the subject did not receive the attention it merited, either at 
the hands of the hospital authorities or the police, to whom 
deaths outside hospital were reported. The figures for any 
year are not strictly accurate, for often a native deliberately 



DROP IN DEATH RATE 315 

gives a fictitious address on entering hospital — they are, however, 
sufficiently accurate for general comparisons. 

In 191 S a severe influenza epidemic spread over the whole 
country, and probably many of the deaths returned that year 
as due to fever were really influenza deaths. 

Drop in Death Rate not due solely to Malaria Advisory Board. 

The great drop in the general death rate from 39-02 in 
191 1 to 26-36 in 1919, that is 12-66 per mille population, must 
not be attributed solely to the action of the Malaria Advisory 
Board. The average fever death rate for 1908 to 191 1, the 
period in which clearing of valleys was not followed by efficient 
drainage, was 9-57; that of 1912 to 1919, the period in which 
clearing was accompanied by efficient drainage, was 5-53, a drop 
of 4-04 per mille only. (1918, being the influenza year, is not 
counted.) 

Malaria, of course, has an influence on other diseases, and 
the drop in the fever death rate does not indicate the total 
improvement brought about by abatement of the disease. 
Again, the operations of the Malaria Advisory Board were 
not the only anti-malarial measures being carried out in the 
town. The Health Officer's staff and the Sanitary Board staff 
had not been idle, and a considerable amount of oiling and 
minor works had been done. 

It is not unfair to the Malaria Advisory Board to attribute 
half the total drop in the death rate to their operations and 
the other half to the improvement in the health conditions 
brought about by the Health Department of the Sanitary 
Board. 

Confirmation of Pratt and Fletcher's Theory. 

In 1912 Dr C. Strickland came to this country as Medical 
Entomologist to carry out research in connection with the 
biology of mosquitoes. In 1915 this officer published a paper 
giving the results of his research in hilly lands. His experiences 
coincided with those of Pratt, Fletcher, and Wellington, in that 
he found wooded valleys practically free of larvae of malaria- 
carrying anophelines, while cleared valleys contained them. 
He said that hilly land, provided the valley were left alone, 
was not malarious, and that hilly land with cleared valleys was. 
He advocated the non-clearing of valleys in the vicinity of 



316 THE MALARIA OF KUALA LUMPUR 

habitations, and recommended that those cleared should be 
allowed to revert to their original state. The matter was 
taken up by the Press and given full publicity. Pratt and 
Fletcher seem to have been forgotten, for their names were 
never mentioned. The theory was called " Strickland's Theory," 
and that is the name by which the public knows it to-day. 

Malaria Advisory Board acknowledge Danger of 
Clearing Valleys. 

The Malaria Advisory Board now for the first time give 
the theory serious attention, and apparently it became con- 
vinced of its truth, for in August 1916, in a circular issued 
from the Federal Secretariat setting forth the aims of the 
Board, the following statement occurs : — 

" 4. The Board aims at the extermination of anopheles 
mosquitoes in all thickly populated centres, and wherever 
economically possible in rural areas, and wishes to effect a 
reduction in mosquitoes generally. 

" The means to be adopted are — 

(«) 
(*) 
to 

w 

(e) Non-disturbance and encouragement of dense natural 
growth in ravines and swamps where effective drainage 
is not carried out, and where the conditions are such 
that this course will result in preventing the formation 
of anopheline breeding-places." 

This, in other words, is the warning of the Malarial Com- 
mittee issued in 1907, consequent on Pratt and Fletcher's 
discovery. Nine years were allowed to elapse before the 
theory received formal recognition. 

Summary of Work done by Malaria Advisory Board. 

At the end of 1917 the area maintained by the Malaria 
Advisory Board was 4500 acres (over 7 square miles). The 
drainage completed included 65 miles of subsoil piping, 
8£ miles of open masonry channels, and 12 miles of open 
earth channels. 

The following figures taken from the Board's report for 



CONCLUSIONS 



317 



1918 show the money expended in anti-malarial works in 
Kuala Lumpur : — 





roar. 


Constructiou. 


Maintenance • 


Total. 




1908-1911 


$47,705 


|6,g86 


$54,691 


Malaria . . -j 

Advisory 
Board . 

Expenditure . -j 


1912 

1913 
1914 

1915 
1916 
1917 


137,526 

68,459 

22,314 

8,988 

23,054 
23,630 


$5,559 
11,118 
11,156 
10,705 
10,487 
10,205 




$183,971 


$59,230 


$243,201 



How much of this would have been necessary had Pratt 
and Fletcher's theory received due recognition and the valleys 
been left in jungle, it is difficult to say. One thing, however, 
is certain, the valleys had either to be left absolutely alone 
or cleared completely and thoroughly drained, for where so 
efficient a carrier as A. maculatus is concerned partial measures 
are inadmissible. To keep the valleys in such a town as 
Kuala Lumpur undisturbed, fencings and an efficient system 
of patrol are essential. Nothing short of this will prevent 
the Asiatic citizen from trespassing and interfering with the 
natural growth. Probably sooner or later clearing would have 
been found necessary. 

Conclusion. 

The story of the rise and subsidence of malaria in the hill 
land of Kuala Lumpur has been told at some length, for it 
is of much interest. 

There is no doubt that the clearing of the valleys started 
malaria in the European residential area, and increased the 
incidence and death rate in the town generally. 

The findings of Pratt, Fletcher, and Wellington showed 
the relative harmlessness of jungle-covered ravines, but those 
findings were disregarded. 

From 1906 to 191 1 the residential area became progressively 
more malarious, and the anti-malarial campaigns carried out 
by the Public Works Department did more harm than good. 

In 191 2 a suitable system of drainage was laid down at 



318 THE MALARIA OF KUALA LUMPUR 

considerable expense ; the malaria disappeared from the hills, 
and the death rate in the town fell considerably. 

Kuala Lumpur stands as an expensive warning against 
interference with jungle ravines in " Inland Hills," unless 
provision has been made for draining those ravines bone-dry, 
and maintaining them in that condition. 

The lessons taught by the three anti-malarial campaigns 
(1908, 1910, and 1912) are: — 

(1) That anti-mosquito schemes cannot be a success unless 

framed and carried out under the supervision of those 
familiar with the habits and life-history of the species 
it is intended to get rid of. 

(2) That a scheme suitable for the eradication of one 

species of mosquito is not necessarily suitable for 
another. The methods found successful in the case 
of A. umbrosus proved worse than useless in the case of 
A. maculatus. Schemes suitable in one country should 
not be slavishly followed in another where the mosquito 
fauna is different. A thorough mosquito survey is an 
essential preliminary to any scheme, and the scheme 
should be framed according to the mosquito findings. 

(3) That a problem full of indeterminate elements is im- 

possible of solution without trials and experiments; 
unforeseen difficulties are certain to arise in the course 
of the work, and allowance should be made for any 
deviation from the scheme which may prove necessary. 
In many cases the estimate of costs can only be a 
guess, and a scheme should not be allowed to fail for 
want of a little extra money. 

(4) That in hill land clearing of valleys unless followed 

by efficient drainage is dangerous, as it promotes 
facilities for the propagation of the dangerous carrier 
A. maculatus. 

Note on Kuala Lumpur by Malcolm Watson. 

To the interesting chapter written by Dr Wellington, there 
is little to add, except on two points. By 1910, over three 
years had passed since the inception of the anti-malarial work 
in Kuala Lumpur ; yet malaria was becoming more and more 
severe; mosquito-control and malaria-control had proved a 



NOTE ON KUALA LUMPUR 319 

complete failure. It was even said that a place once 
particularly free from malaria had become intensely malarious 
as a consequence of the anti-malarial campaign. Money had 
been spent on open drains, on rubble drains, on concrete 
drains, and subsoil drains — without success. Government now 
appeared to be disinclined to spend more money ; possibly 
because it seemed like throwing good money after bad. In 
June 1910, at Dr Travers' suggestion, I gave a public lecture 
in Kuala Lumpur, and explained the problem. I urged the 
need for research, the creation of a Sanitary branch, and 
co-operation between all branches of the Department of 
Medicine, namely hospitals, research, and sanitation. 

Throughout the remainder of 1910 and most of 191 1 
practically nothing was done in Kuala Lumpur. To me it 
was a period of anxiety. I had advised some estates to lay 
down a system of subsoil drainage to overcome A. maculatus, 
and some had agreed to do so. But it was hopeless to expect 
much progress throughout the country, when the Federal Capital 
was notorious as an anti-malaria failure. Indeed I feared that 
the failure in Kuala Lumpur might be to the Malay States 
what Mian Mir was to India. At Mian Mir the Imperial 
Government of India and the Royal Society of England 
joined forces to eradicate malaria from the Cantonment. It 
is unnecessary here to go into details ; but the experiment was 
a failure. Sir Ronald Ross 2 says of it : " In fact the whole 
affair was conducted on unpractical and unscientific lines. It 
proved nothing at all, and its only effect was to retard anti- 
malaria work in that and other countries for years." 

For anything like that to occur in the Malay States, where 
so promising a start had been made ten years before, would 
indeed have been a disaster. Government, however, did not 
move for over a year ; but on the formation of the Malaria 
Advisory Board at the end of 191 1, I urged the importance of 
clearing away the malaria of Kuala Lumpur, as the first duty 
of the Government. The system I had devised for Seafield 
Estate was adopted, as is described in the Annual Medical 
Report for 191 1 ; and its success is due to the careful way in 
which it was carried out by Mr Evans, the Board's engineer. 

The only other point I propose to mention is the importance 
of continuous and ample malaria research. Our ignorance of 
the distribution of A. umbrosus has cost this country heavily 



320 THE MALARIA OF KUALA LUMPUR 

both in money and in lives. I was familiar with the Coastal 
Plains and Coastal Hills, with jungle and the jungle-loving 
A. umbrosus and A. aitkeni. Dr Leicester had caught A. 
umbrosus in Kuala Lumpur ; and some specimens of the 
mosquito had been taken by a gentleman in his house in 
Kuala Lumpur and given to me. I had known many curious 
instances of the appearance and disappearance of the insect. 
Sometimes enormous numbers would disappear in a few days. 
At times it is easily got : at other times not. Therefore I 
attached little or no importance to Mr Pratt's, Dr Fletcher's, 
and Dr Wellington's failure to find the insect in ravines. 
These gentlemen, on the other hand, had no knowledge of the 
Coastal Plains and Coastal Hills, in which A. umbrosus abounds- 
Thus no one realised that the distribution of A. umbrosus was 
so peculiarly limited ; and that Kuala Lumpur and Batu Tiga, 
which are only some ten miles apart, and apparently in similar 
hilly land, were in different zones; the ravines of one harbour- 
ing A. umbrosus, those of the other not ; from a malarial point 
of view, a difference of first importance. Not suspecting the 
truth, I was greatly puzzled by many places, as I have described 
in the chapter on "Inland Hills"; and it was not until Dr 
Strickland informed me of his discovery of the absence of 
A. umbrosus from certain hills, and after my visits to Pahang 
and Batu Arang, that the truth seemed to be found ; namely, 
that A. umbrosus was limited to the Coastal Hills, and did not 
spread to what may be called the " Inland Hills." Had there 
been more research, in 1909, as Dr Wellington suggests, the 
truth would have been discovered sooner : and in the extensive 
clearings subsequent to the Rubber Boom in 1910 many a 
ravine would have been left in jungle, to the great advantage 
of the public health. As it was, the importance of what had 
been discovered by Messrs Pratt, Fletcher, and Wellington 
was not appreciated ; the truth had to be rediscovered by Dr 
Strickland. Even then Government was slow to believe it ; 
and the treatment meted out to Dr Strickland is a blot on the 
name of the administration of this country. 

To sum it up, the administration in the past has not 
provided sufficient malarial research nor encouraged it ; and 
for lack of knowledge large sums have been wasted on badly 
designed or unnecessary work, progress has been spasmodic, 
and an enormous number of lives have been lost. 



CHAPTER XXVII 

ANTI-MALARIAL WORK IN SINGAPORE 
By P. S. Hunter, M.A., M.B., D.P.H., Deputy Health Officer, Singapore. 

Prior to 191 1 only temporary measures such as oiling of 
swamps, filling of pools and the clearing and training of streams 
and ditches had been carried out, and nothing very permanent 
had been attempted. In that year, however, in the pandemic 
of malaria, Singapore suffered fairly severely, and it was felt 
that something more radical must be done to combat the 
disease. 

In his annual report for 1910, Dr Middleton, the Health 
Officer, had suggested that a wise course would be to institute 
"' a systematic examination of school children for signs of 
present and past malaria, ascertain the locality of their present 
or recent abodes, and make an inspection of these localities 
for conditions contributing to the disease." This actually was 
done in 191 1 by Dr Middleton himself and Dr Finlayson ; and 
they found that the most malarious district in Singapore was 
the Telok Blangah area. In August 191 1, in the two Malay 
Vernacular Schools of that district, Telok Blangah School and 
Kampong Jago School, 46 per cent, and 295 per cent, 
respectively of the children were found to have enlarged 
spleens. 

The district extends from the General Hospital to Morse 
Road and forms a strip of land a half to one mile wide along 
the harbour. Consisting as it did of large swampy low-lying 
areas at its eastern end, and hilly ground with its accompanying 
ravines and streams at its western end, it was felt that it was 
an extremely suitable area with which to experiment. It was 
known to be malarious and was not too large to make super- 
vision difficult. Accordingly Dr Malcolm Watson, whose anti- 
malarial measures had been so successful at Port Swettenham 



322 ANTI-MALARIA WORK IN SINGAPORE 

and Klang, was asked to advise as to the best method of 
dealing with the problem. 

Dr Watson first confirmed the findings of the spleen rates 
in the schools ; and, further, to get more children and to 
determine more exactly the foci of malaria, made a house- 
to-house examination. In all, 571 children were examined, 
and 21 per cent, were found to have enlarged spleens. In 
the course of the examination, too, it was found that the hilly 
part of the district with its ravines and streams was much 
more malarious than the low-lying flat lands. 

Thereafter a detailed examination of the whole district 
was made to determine the varieties of anophelines breeding 
in the different localities. 

Depending on the conditions existing at each area, spleen 
rates, species of anophelines, and the variety of swamp or 
stream, Dr Watson made his recommendations — filling (though 
he was not in favour of this generally) earth drains, hill-foot 
drains, brick drains and subsoil pipes. 

To the newly-formed Anti-malarial Committee the task of 
carrying out these recommendations was entrusted, and under 
the supervision of Dr Finlayson, the work was immediately 
put in hand. During the period of construction quinine was 
distributed free in the district, and an effort made toward 
the education of the people in the habits of mosquitoes by 
the exhibition of illustrative cards in the markets, schools, 
and public places generally. 







Total 


Total show- 




School. 


Date. 


ing Spleen 


Percentage. 






iLXtLnuncQ* 


Enlargement. 




Telok Blangah 


191 1 August . 


39 


18 


46-1 




191 1 November 


37 


18 


48-6 




1912 April 


52 


26 


50-0 




1913 January . 


58 


12 


207 




191 3 May 


59 


7 


II-O* 




191 4 January . 


54 


7 


13-0 




1914 September 


49 


4 


8-1 




191 4 November 


54 


2 


3-7 


Kampong Jago 


191 1 August . 


44 


13 


29-5 




1912 April 


45 


8 


17-7 




191 3 January . 


57 


8 


15-7 




1913 May 


40 


3 


7-5 




1914 January . 


49 





O'O 




1914 September 


46 


3 


6-5 



Alinust. 



EXPERIMENTAL AREA SELECTED 323 

The work was completed early in 1914. Whilst it was 
going on, and just after completion, Dr Finlayson made several 
exhaustive house-to-house examinations of the children in the 
district. The figures are instructive. In April 1912, 508 were 
examined and 11-4 per cent, were found to have enlarged 
spleen. In April 1913, out of 485 examined, not quite 4 
per cent, were similarly affected. The figures for the two 
schools during the period are shown in the table on the 
previous page. 

A review of these figures shows that there was a progressive 
decrease of the spleen rate to practically zero. 

During the war the regular examination of these children 
could not be carried out as frequently as one would have 
wished ; but I visited the schools at intervals and never found 
any indication that the spleen rates were rising. My last 
examination was a few days ago, when I found at Telok 
Blangah School two children with spleens just palpable, out 
of a total of fifty-two, and at Kampong Jago School, one child 
out of thirty-one. 

All these figures speak for themselves, and I feel I cannot 
do better than to sum up in the words used by Dr Watson 
in his second report of December 1914: — 

" Three years ago it was decided to attempt to control 
malaria in the area of Telok Blangah by abolishing breeding- 
places of the mosquitoes which carry the disease : the spleen 
rate was used as the test of the amount of malaria in the 
district, and by that test has been shown to have decreased 
to what for all practical purposes may be called zero. Similar 
measures carried out in other places have had similar results, 
and the Anti-malarial Committee of Singapore may, with 
confidence, look on the reduction of malaria in the Telok 
Blangah district, not as a mere accident, but as the direct 
result of the work done." 

If there should have been any doubt as to the truth of 
these words in 1914, there can certainly be none now after 
the lapse of another five years. 

The actual expenditure on the works was under $50,000, 
and a certain amount of that was spent on anti-malarial 
measures outside the area — a wonderfully small figure in 
consideration of the great results achieved. 

From 1 9 14 onwards it has been part of my duties to keep 

Z 



324 ANTI-MALARIA WORK IN SINGAPORE 

watch on these areas and to look out for defects. The 
experience gained has been invaluable in enabling me to 
come to a decision as to the best method of dealing with 
anopheline breeding-grounds in other parts of the municipal 
area. 

Regarding the low-lying eastern part of the area, there 
is nothing much to say. It was originally swamp and was 
drained by open-earth drains. These open ditches are much 
the same as when first cut. They certainly dried up the 
ground, but they are too many and are a source of danger 
in themselves. But this point I shall refer to more fully later. 
Occasionally anophelines are found breeding in them, usually 
A. rossii, sometimes A. karwari, and rarely A. maculatus. 
By constant cleaning by the maintenance gangs and oiling 
where necessary, this breeding is kept down, but I am afraid 
that this part will never be successfully drained until the 
Singapore Harbour Board take steps to permanently lower the 
level of the subsoil water in their reclamation, through which 
the drainage of this whole area ultimately passes. It is purely 
an engineering problem. With some system of tidal valves 
it should not be impossible. 

Turning to the hilly western end of the area it is interesting 
to note that sooner or later, as Dr Watson had forecasted, 
A. maculatus was found breeding in all the ravines — very 
often in the open-earth foot-hill drains that we ourselves had 
cut. The Radin Mas area is one of the best examples of 
this. It is a large wide ravine about half a mile long, with 
a stream winding down the centre. Off the larger ravine 
five smaller ones, each several hundred yards long, open. In 
the original scheme it was recommended that the two top 
ravines only be piped, which was done. Then A. maculatus 
appeared in the spillways, necessitating the concreting of these 
spillways right down to the main stream. Later, all the other 
three ravines in which we had cut open drains began to 
show A. maculatus, so that these in turn have been subsoil-piped 
down to the main stream in the middle of the valley. On 
my last visit to this area in December 1919, I examined about 
twenty children in the Malay village there, and found none 
with enlarged spleen. The older inhabitants, too, assured me 
that there was no fewer now in the kampong. 

I have followed the same policy over the whole of this 



ANOPHELES MACULATUS 325 

area. Roughly, wherever A. maculatus has appeared, I have 
dealt with the breeding-ground by subsoil piping. Open earth 
drains are all right at first, but they require constant super- 
vision ; and with the repeated cutting and cleaning that they 
are subjected to, they ultimately become too wide and deep, 
so that water stagnates in them. 

And this brings me to a point which I wish to emphasise 
with regard to the habits of A. maculatus. In my experience 
the dry weather is the time to be on one's guard against this 
mosquito. In the very dry spell from August to October 1914, 
when we had practically no rain for three months, I found more 
A. maculatus breeding-grounds both in the experimental district 
and in the municipal area generally than in the several years 
since. The reason is not far to seek. In wet weather the 
larvas are being constantly flushed out from the smaller drains 
and never get a chance to develop. But I emphasise the point, 
because I found that in many places by cutting open drains 
breeding-grounds for A. maculatus had been created. After a 
little dry weather there is no water in the ditches except 
that coming from the springs, the outlets of which have been 
exposed by the cutting of the ditch itself — such a spring is 
an ideal breeding-ground for A. maculatus. 

The danger of this is well illustrated in the following. A 
certain bungalow in the residential area stood on the high 
ground adjoining a large stretch of flat land. This low-lying 
flat land was originally a swamp, but had been drained by 
the cutting of several large, open ditches through it. At the 
time of which I speak, the weather had been very dry, and 
these open ditches, which usually stood half full, were empty 
and dry in their upper reaches. Two Europeans in the 
bungalow were suffering from malaria, while among the native 
servants and their children there were other six acute cases. 
The only anopheline breeding-ground found was in one of 
these aforesaid dry ditches close to the house, where a small 
spring oozed from the side of the ditch, ran for a few feet, and 
finally disappeared in its floor. About half a dozen A. maculatus 
larvae were found in the whole spring. It was piped at the 
cost of a few dollars — and there were no further fresh cases 
of malaria. 

In the experimental area I had much the same experience 
with two private reservoirs. Both these had been formed by 



326 ANTI-MALARIA WORK IN SINGAPORE 

the simple process of bunding across a ravine. The sides of 
the reservoirs were formed by the grassy banks, and the floor 
by the natural slope of the ravine. Under the scheme the 
springs in the ravine-collecting area above each reservoir had 
been dealt with by pipes, the outlet of which delivered over 
a spill-way directly into the reservoir. All that was necessary 
was thought to have been done. But in a dry spell the water- 
level of the reservoir fell, and a large expanse of sloping floor 
was exposed. In this exposed part were numerous springs 
which showed themselves as trickles of water running down 
to the water-level. My attention was first drawn to the danger 
by the occurrence of several cases of malaria in houses over- 
looking one of these reservoirs. I found A. maculatus breeding 
in these springs. A similar condition of affairs existed in the 
other reservoir. The fault was remedied by a little rough 
concreting and excavation of the floors. 

From these and similar experiences, I concluded that the 
best way is to put down subsoil pipes wherever possible. The 
pipes in the area, some of which have been down for over 
six years, are still working perfectly, and there need never 
be any fear in employing this method of drainage. All that 
is necessary is to see that the pipes are of good strong material 
and that due allowance is made for storm-water, i.e., the pipes 
must be many times bigger than those capable of taking the 
ordinary dry weather flow. 

Once pipes have been put down in a ravine all that is 
necessary is that the maintenance gangs should visit the area 
at regular, short intervals to cut down the blukar and other 
secondary growth which soon springs up. If this is religiously 
done for eighteen months to two years, it is my experience to 
find that these coarser growths tend to die out, and are replaced 
by a firm, springy turf which no amount of storm-water will 
dislodge, and which requires a minimum of supervision and 
expenditure in upkeep. 

With regard to the maintenance of these anti-malarial 
areas after completion, there is one difficulty we have had in 
Singapore to which I feel I must make reference — and that 
is the trouble we have had to keep Chinese squatters from 
settling in the area — or to evict them once they have settled. 
Dr Watson, in his 1914 Report, wrote very strongly on the 
subject. Just recently I found that one of the Radin Mas 



EXTENSION OF THE WORK 327 

ravines had been converted into a huge vegetable garden. 
Wells had been dug over the pipes, and the area was slowly 
reverting into a worse condition than ever before. I say 
worse, advisedly, because the squatter, in addition to breeding 
mosquitoes, by keeping night-soil pits and using night-soil 
in his gardens, directly encourages the spread of diseases 
like typhoid, cholera, and dysentery. I feel that I cannot 
emphasise too strongly that no cultivation of any kind should 
be permitted in these areas. 

Turning now to areas with which I am more familiar, 
because I have supervised them from the start, I have tried 
to put in practice the various lessons learned from the Telok 
Blangah area. During the past six years new works have been 
constructed all over the town, but mostly in the residential 
districts. This residential area is essentially a hilly area, and 
roughly it is a system of small ravines, with the houses built 
on the sides. In the ravine was a swamp or a winding over- 
grown stream, with wet, muddy banks and springs oozing out 
at the foot-hills — all ideal breeding-grounds for A. maculatus , 
and sure enough A. maculatus was found sooner or later in all 
of them. To enable me to find the foci of malaria more 
quickly, I made arrangements with the medical practitioners 
to notify me whenever they attended a patient with a first 
attack of malaria. I found this very useful as, whenever I 
received notice of several cases in one locality, I visited the 
spot and found the anopheline breeding-grounds long before 
I should have done in my routine search of the whole 
district. 

Scattered over the Municipality, there were several low- 
lying areas which had originally been swamps and which were 
drained by having open earth drains cut through them. And 
this brings me to a point to which I promised to refer later. 
My experience is that these swamps have had far too many 
ditches cut in them. These have certainly fulfilled their 
purpose in drying up the swamp. But as soon as the ground 
is freed from its water-logged condition these ditches which 
become deeper and wider from the attentions of the maintenance 
gangs, stand half full of water, which is almost stagnant and 
breeds all sorts of mosquitoes. Further, as I have already 
pointed out, there is the danger that in a dry spell the level 
of the subsoil water falls, and springs are exposed in the 



328 ANTI-MALARIA WORK IN SINGAPORE 

ditches themselves. And in these springs A. maculatus breeds. 
And even without waiting for a dry spell we may find we 
have created A. maculatus breeding-grounds, as it frequently 
happens that with the drying up of a swamp the springs at 
the surrounding foot-hills are exposed. This was the condition 
of things in many flat areas in Singapore — and, as already 
pointed out, is the condition found in the eastern end of the 
Telok Blangah area itself. So far as possible with these areas, 
I have tried to eradicate the A. maculatus breeding-grounds by 
subsoil piping all the springs at the foot-hills down to a main 
drain. 

A swamp prior to being touched may, of anophelines, be 
breeding only A. sinensis ; and, if by draining it, we are simply to 
create a suitable breeding-ground for a more dangerous species, 
it had much better be left alone. So that it is obvious that, 
if we must drain, it must be very carefully done. Remembering 
these things, I undertook the drainage of a large swamp some 
60 acres in extent lying behind Tanglin Barracks and extending 
from there to the Singapore River at Alexandra Road. 

The natural drainage of the swamp was by way of the river. 
The swamp itself was knee-deep in water practically all over, 
and almost anywhere one could find A. sinensis larvae. The 
river was first cleared of silt in its lower part. In the process of 
clearing the river, about four dams, put in by Chinese squatters 
for the purpose of diverting water to their pig and duck ponds, 
were demolished. The course of the river, too, in its part 
adjoining the swamp, was cleared and straightened. 

These simple measures in a month's time did much to do 
away with the swamp. The removal of the dams lowered the 
river between two and three feet and permitted the water from 
the swamp to drain away. Large areas of it became quite dry 
as the level of the subsoil water fell. 

Thereafter one main drain was cut through the centre, with 
two smaller ones joining this and draining two ravines, which 
formed the head of the swamp. These, after a little time, were 
sufficient to completely dry the area until one can, to-day, walk 
over it in the wettest weather and find no water showing 
anywhere. But, and herein lies the danger, springs began to 
show at the foot-hills. As the area was well outside the 
residential part and there were no houses near, these springs 
were treated by being drained into the main drains by small 




%Mm 







Fig. 108.— Singapore. 
Open Ditch into which the subsoil drains discharge. 



[To face pace 323. 



DRAINAGE OF RAVINES 329 

open ditches. The big ditches I never find breed anophelines ; 
but the small ones especially, if allowed to become grassed over, 
most certainly do. Now the ideal to aim at, in my opinion, is 
that all these springs should be subsoil piped to the nearest 
main drains. In this case, it would have been done but for 
lack of money. But already, with the demand for houses, 
construction is progressing on the sides of one of the ravines, 
and knowing the danger, I have advised that we immediately 
replace the main open drain in the ravine by a cement 
channel, and the small ditches tapping the springs by subsoil 
pipes discharging into this channel. And the work will be 
commenced at once and completed before the houses are 
occupied. 

This brings me back to the method followed in the more 
purely residential areas with its system of narrow ravines. 
It is essentially the same as that for the swamp but more 
advanced. Originally I drained the marshy ground in the 
floor of a ravine by one open earth drain, or by clearing and 
straightening the existing stream. Then all springs were led 
by contour or foot-hill subsoil pipes to discharge over a 
concrete spillway into this. The main drain was left as an 
open ditch, and, practically without exception, I have never 
found them breeding when they are kept reasonably clear 
of obstructions, and pools are not allowed to form. But, with 
the rapid extension of the town, the more rigid insistence that 
houses should have a proper drainage scheme, and the care 
required to keep these open ditches from silting up, I have 
lately come to the conclusion that they must be replaced by 
a more permanent type of drains. One that our engineers 
have found very successful and not too expensive is a V-shaped 
open concrete channel with concrete slab revetments and turfed 
sides — the idea being that the ordinary dry weather flow is 
conveyed within the concrete area, flood water only reaching 
as far as the turf. After a time with reasonable supervision 
these turfed sides become firm and no amount of storm water 
will break them down. Into these drains the house drains will 
discharge. What is more important is that many people, 
despairing of ever seeing a proper water carriage sewage 
system installed, are putting in their own septic tanks and 
contact beds. The effluent from these in many cases must go 
by way of the ravines ; and I, personally, have no objection to 



330 ANTI-MALARIA WORK IN SINGAPORE 

its being discharged into the main drains — provided the septic 
tanks are properly supervised and the main drain is concreted. 

I made the experiment in one locality of combining the 
ordinary house drainage with the subsoil pipes. The house 
drains, which carry rain and bath water and kitchen washings 
only, were made to discharge over a sump. I would further 
advise that when this is done a grid should be interposed in 
the house drain to intercept refuse like egg-shells, etc. — which 
the cook insists on putting down the drain. 

Further, this grid should be placed well inside the compound 
where it will catch the householder's eye. He certainly won't 
look for it. 

Though this experiment was quite successful, I don't 
generally advise it. It is preferable to have house drains 
discharging into an open channel. I simply mention it 
because a case might easily arise where, to reach a main 
drain, the house drains might have to be prolonged for 
hundreds of yards, and a combination such as I have described 
would prove much less costly. 

With regard to the flat lands in the municipal area with 
its many pig and duck ponds and the other varied collections 
of water, so dear to the heart of the Chinese vegetable gardener, 
nothing much has been done. Indeed, during the war nothing 
was allowed to be done. All that was possible was to keep a 
close watch on the larvae inhabitants of these ponds. Of 
anophelines only A. sinensis is ever found, though of course 
many other mosquitoes find a breeding-place there. 

Difficulty was experienced with three flat areas, all tidal, 
in that A. ludlowi periodically bred out in enormous numbers. 
Two of these were dealt with by filling, as they were simply a 
series of pools into which the sea water reached at high tides. 
The third was in the Telok Blangah area in the reclamation 
adjoining Nelson Road. 

Here all the open ditches occasionally bred A. ludlowi literally 
in millions. The only possible course was to deal with it by 
oiling, which is now regularly done. A point of interest in 
connection with this last is, that in his 191 1 report Dr Watson 
was at a loss to account for the fact that at Spottiswoode, the 
cleaner end of this area, there was so little malaria compared 
with what was found at Nelson Road, its fouler end. He 
suggested as a reason that some other anophelines might be 




Fig. 109. — Singapore. 
The new type of permanent Drain into which the subsoil drains discharge. 

[ To face page 330. 



PRIVATE OWNER OR RATEPAYER 331 

breeding in the Nelson Road district. I have no doubt in my 
own mind that M. ludlowi was the culprit. 

Just recently a new Anti-mosquito Ordinance, has been 
passed by the Legislative Council, though it has not yet been 
out in operation. Under it there are ample powers to deal 
effectively with all these low-lying areas. 

Practically all these works described above have been done 
at municipal expense. I found very early that, if one had to 
wait for the owner of a property to carry out the drainage, 
one might wait for ever. And, apart from that, it is almost 
impossible to assess the cost for each owner or to estimate how 
much his property benefits. The following will illustrate what 
I mean. In 1914, certain houses, under different ownership, 
built on high ground surrounding a ravine, were rendered 
untenable on account of malaria. In the floor of the ravine 
was a small cocoanut plantation. The water from the high 
ground showed as springs only in this plantation, and were all 
breeding A. maculatus. These were subsoil piped in the usual 
way with the result that malaria disappeared. Now it would 
obviously have been unfair to make the owner of the plantation 
pay. In any case he was a poor man and to pay would have 
meant bankruptcy. It was equally difficult to estimate the 
amount that each owner of the houses should pay, and there 
was no machinery for enforcing payment without endless 
litigation. Consequently the only thing to do was, what was 
done — to pipe the area at municipal expense. In my sub- 
sequent works this is pretty well the policy I always followed. 
But with the passing of the Anti-mosquito Ordinance and the 
likelihood, one hopes, of things being done on a much wider 
basis all over the island and money being spent on a lavish 
scale, it will be unfair any longer to put the whole burden on 
the taxpayer and the big property owners must be made to 
pay, at least in part. 

Regarding the cost of these works it is not of much use my 
quoting figures. The prices of to-day bear no resemblance to 
those of a year ago, I had almost said yesterday ; the upward 
rise in the price of materials being so rapid. But this I will 
say, that in carrying out anti-malarial — as against anti-mosquito 
works — I have often found that for a little judicious expenditure 
wonderful results may be obtained. 

I should now like to describe my experience of what may 



332 ANTI-MALARIA WORK IN SINGAPORE 

be done in the way of controlling malaria in, say, a small self- 
contained district like a small island. 

During the war I was mobilised with the local volunteers, 
and late in 191 5 was sent as medical officer in charge on 
Blakan Mati. 

This island has a European population — mostly Garrison 
Artillery, of about 500. It is situated at the western entrance 
of the harbour, is about 3 miles long by a half to three quarters 
broad, and consists of high ground running its whole length 
with fairly steep slopes to the sea on eitherside. The northern 
side is fringed with mangrove, while the southern slope ends in 
cliff and sandy beach. The high ground on which the forts 
are situated is intersected with ravines which are full of tiny 
streams and innumerable springs. 

I had known, prior to my going to live on the island, that 
malaria was rife amongst the troops ; but until I saw my 
morning sick parade, I did not realise how bad it really was. 
And, if that were not enough, I was forcibly reminded that 
something must be done by finding several A. maculatus adults 
on my verandah in the first week of my occupation of the 
bungalow. 

An anopheline survey of the whole island was immediately 
undertaken. About twenty anopheline breeding-grounds were 
found. A. umbrosus and A. karwari were found in one or two 
places ; in all the others our old friend A. maculatus. 

Prior to 191 5 very little in the way of permanent works 
had been done. A few pipes had been put down in places ; 
but these were not acting as the undergrowth had been allowed 
to grow down into them. Mostly there were open earth drains 
with oil-drips. I may say that these drips, in a place like 
this at any rate, where the person responsible for their upkeep 
is continually being changed, are useless, and may even be 
dangerous from the false sense of security which they may give. 

From my experience in Singapore, I determined that the 
only method to ensure success was to put down subsoil pipes ; 
and this work was accordingly put in hand immediately. 
While the work was going on, temporary measures, as oil 
spraying regularly applied, were carried out. 

Several difficulties were encountered in the course of the 
work. At one place just below the barracks, a series of springs 
were found below the level of high tide, but protected from 




Fig. no. — Singapore. 
Both subsoil drainage and the effluent from the small septic tank seen in the photograph, 
discharge into this permanent concrete drain. 

[To face page 332. 



BLAKAN MATI 333 

the sea by a sand bar. The difficulty was overcome by the 
subsoil pipes being brought to discharge below high-tide level — ■ 
a system which was found to be quite satisfactory. Then again 
difficulty was experienced at a wet area artificially created 
by the raising of the natural subsoil level to supply water for 
the Dhoby ponds. In wet weather there was formed a large 
swamp several acres in extent, on the confines of which 
maculatus, kariuari, and umbrosus were found breeding. As it 
was insisted that the Dhoby ponds must have an adequate 
supply of water, the drainage of this area was rendered rather 
difficult. The problem was cleverly solved, however, by the 
engineer who tapped two springs outcropping at a higher 
level some quarter of a mile away. These were led by an 
open concrete channel to the Dhoby ponds, and proved to 
give a sufficient supply. The swamp was then drained by 
very deeply-laid subsoil pipes, and the whole area became 
dry and remained so, even in the wettest weather. 

On the very steep slopes of Serapong, the highest part 
of the island, we had trouble in the ravines with storm water. 
It came down so forcibly that it washed out the newly-made 
ground covering the pipes in the floor of the ravines. This 
was overcome by cutting a temporary channel in the side of 
the ravine, well clear of the subsoil pipes. After a time, when 
the floor of the ravines developed a strong firm turf, the storm 
water could do no harm. 

Except for these and several minor difficulties, the work 
was easy. Roughly, the same principles were followed as in 
Singapore, except that on Blakan Mati the subsoil pipes were 
brought right down to the sea in most cases, instead of 
discharging into main open channels. 

The drainage was completed in two years, that is by the 
end of 1917. In a report of April 1917, by the Engineer-in- 
charge of these works, I find that during 1916 a sum of 
£576 was spent, and that a further sum of £500, which, it 
was estimated, would easily complete the programme, was 
granted for 191 7. It was further estimated that a sum of 
£200 would be required annually to keep the 60 acres occupied 
by these drains clear of vegetation. Personally, I think this 
sum rather high, as I feel certain that the coarse, thick- 
vegetation will die out in two years, to be replaced by short 
turf, that will require a minimum of expenditure and super- 



334 ANTI-MALARIA WORK IN SINGAPORE 

vision. Naturally, at the present day, these figures are 
valueless — and possibly they are not exact, in that a good 
deal of money seems to have been spent on the areas in 
previous years in clearing jungle, cutting open drains (and 
incidentally creating maculatus breeding-grounds), oiling, etc., 
some of which money might have been required to be spent 
on the permanent works. But I only mention the figures 
because the engineer assured me on the completion of the 
work that the actual cost was only three times as much as was 
being spent in any one year on purely temporary measures. 

In the following list of admissions for malaria, I have 
excluded those for Asiatic troops, as it would not be fair to 
include these. On the island there was always a detachment 
of the Johore military forces. They suffered a good deal from 
malaria, but as they were relieved every fortnight, their malaria 
was obviously contracted elsewhere. So, too, with the Indian 
gunners stationed on the island. It may be that during the 
war medical examination was less strict. At anyrate, within 
a day of their arrival on the island, I have found recruits with 
enlarged spleens. Prior to 1914, the average number of 
European troops was in the neighbourhood of 350, and after 
that date about 260. During my stay on the island, many of 
the men belonged to B category and were suitable subjects for 
the depredations of the malarial parasite. The figures, so far as 
I could collect them from the hospital records available, were : — 

Admissions 
Year. for Malaria. 



1912 

1913 

1914 
1915 
1916 
1917 



163 

94 
48 
87 
23 
26 



In 1916 and 1917 there were only sixteen and fourteen 
fresh cases respectively, the others being readmissions. I was 
unable to find the corresponding figures for previous years. 
On my return from home in 1919, I was assured that there 
had been no fresh cases of malaria in 191 8, and to the best 
of my knowledge there were none in 1919. 

At the risk of appearing tedious I wish in conclusion to 
reiterate one or two points. It may be argued that the system 
of drainage I have advocated is expensive, as it certainly would 



RESULTS 335 

be on, say, a rubber estate. But I do not pretend to advise 
for other than a thickly populated area such as Singapore. 

The anopheline we have to fear in Singapore is A. 
maculatus, and it is more likely to give trouble in dry weather 
than in wet. Whenever it appears, I believe the only sure 
way is to put its breeding-place underground. 

Dealing with a ravine, subsoil pipe the foot-hill springs 
into, if possible, one main open channel. This channel may 
be of the open-earth variety at first, if in a sparsely populated 
district ; but as the town expands, it should be replaced by 
a drain of more permanent type. 

In draining a swamp, don't hurry. Try if anything can 
be done in the way of lowering the outlet, or clearing it of 
obstruction. Wait a little and then cut as few open ditches 
through it as possible. Having done so, and the ground 
having dried up, be on the lookout for springs at the foot-hills 
and surrounding ravines. Don't wait for these to breed, but 
subsoil pipe them immediately into the nearest main ditch. 

Where filling is absolutely necessary, consider always the 
advisability of first putting down subsoil pipes to take the 
drainage of the adjoining higher ground. 

Having constructed anti-malarial drains, see that the areas 
are frequently visited and carefully tended for two years, and 
permit no cultivation of any kind. On this last point there 
should be no compromise. 

Results. — As regards results, I do not intend to quote any 
figures of the reduction of the death rates of malaria. I am 
afraid that, with our present antiquated system of death 
registration, whereby 50 per cent, of those who die are never 
seen in life by a medical man, but are certified (many of them 
as malaria) from an inspection of the body only, any figures 
one might quote would be valueless. But I personally feel 
sure, and I speak, too, for one of our leading practitioners, 
that in the town and its immediate surroundings there is now 
very little malaria contracted. And in any case the results 
obtained in Telok Blangah itself, and on Blakan Mati, are 
enough to convince me that we are working along the best 
lines to finally eradicate the disease. 

There are, however, certain figures which give unequivocal 
evidence of the improved health of the town, namely the 
reduction in the total death rates. These show that, despite 



336 ANTI-MALARIA WORK IN SINGAPORE 

the influenza epidemic, there has been a saving of over 16,000 
lives in the eight years (1912-1919). The remarkable reduction 
in the annual malaria curve shows that no small part of this 
saving of life must be attributed to the anti-malaria work. 
The subject is dealt with in more detail by Dr Watson in 
the section on Singapore in Chapter XXIX., and will be better 
understood after a perusal of Chapter XXVIII., which deals 
with Statistics and the Seasonal Variations of Malaria. 



CHAPTER XXVIII 

ON STATISTICS 

Without statistics no clear idea of the health of a community 
can be formed ; to the sanitarian they are as important as his 
accounts to the merchant. Before he can make out a case for 
the expenditure of money, he must show in statistical form 
the prevalence of the disease he desires to control. From a 
business point of view, statistics are necessary in order to 
determine if the results obtained are worth the money spent. 

The next question that presents itself to the tropical worker 
is, What statistics should be compiled? To that there can 
only be one answer. Every figure that bears on the disease 
should be collected. At the time some figures may not appear 
of much value ; but, if compiled and filed, they may prove of 
extraordinary value at a later period ; such, for example, are 
routine spleen rates. Changes in health may be occurring 
of which the observer is not conscious at the moment ; later 
he will realise them, and can then refer to the old spleen 
rates. 

The statistical departments, which exist in most countries 
in Europe, are practically non-existent in many places in the 
tropics. To a large extent, the worker must compile and 
collate whatever statistics he requires. Generally speaking, 
he works in a narrow field ; and this, apart from the personal 
equation, may lead to error and false conclusions. In this 
chapter I wish to put the beginner on his guard against some 
fallacies ; at the same time show how valuable figures may be 
when local conditions are known. 

Hospital Statistics. — Admissions for malaria, checked by the 
microscope, form series of facts of great value. Unfortunately 
they do not include all cases of malaria, as some may have had 
quinine shortly before admission, or for other reasons the 
parasites may not be found. This error may generally 

337 



338 ON STATISTICS 

be considered as a constant and so be disregarded ; and the 
figures are of great value. 

Out-patients treated for malaria are less likely to have their 
blood examined, and the records are less exact. Both out- 
patients and in-patients may reappear time and again for 
treatment, and it is usually impossible to say if the patients 
are suffering from new infections or relapses. 

Nevertheless the number of admissions and the number 
of out-patients run an almost parallel course in the ordinary 
native hospital, and the gross figures of each, even admitting 
they contain many errors in diagnosis, throw much light on 
the health of a place, and should not be discarded. 

When there is much malaria on an estate, some cases are 
admitted to hospital ; but many are not. For where malaria 
is severe, and the cases are numerous, the hospital accommoda- 
tion is generally insufficient ; this is particularly so when a 
seasonal wave is severe, and 30 to 40 per cent, of the labour 
force is incapacitated. When, however, the malaria has been 
controlled and reduced in amount, it is possible to admit 
every case with an abnormal temperature. The admissions 
for malaria may, therefore, show no great fall, and the observer 
might be misled if he considers merely the admissions ; the 
error can be detected by examining the number of out- 
patients. In the F.M.S. this frequently happens; no cases 
of malaria are treated as out-patients on some estates. 

If some care be taken in ascertaining the exact residence 
of cases admitted to hospital, the observer can add considerably 
to the value of his figures. Having done this for some years, 
when in charge of the Government hospital at Klang, I can 
say that this correction is much less difficult than might be 
imagined ; it demands, however, from the inquirer a fairly 
accurate knowledge of the local details of the country-side 
from which the patients come. When the exact residence 
is known, it is possible to make a " spot map " of the disease. 

On large estates, conditions may vary widely on different 
divisions ; there may be only half a mile between the best 
and the worst health, so the admissions and the daily 
number in hospital from each division should be recorded 
separately. 

The great fallacy of admission rates for malaria as an 
indication of the health of a place is its variation with the 



DEATHS 339 

number of non-immune new arrivals. Many new arrivals will 
raise the admission rate with great rapidity. This is seen 
when a batch of new coolies arrives on a malarial estate. 
If no others come, the admission rate gradually falls, until 
it is so low that the observer may imagine the place has 
become healthy ; but it is not so. Other new arrivals will 
again send up the admission rate. A fall in the admission 
rate by itself cannot, therefore, be regarded as proof of the 
control of malaria. As I will show, the observer can guard 
himself from mistake by ascertaining the spleen rate. 

The observer is liable to be misled by a fall in the admission 
rate (and as will be seen by the death rate), chiefly when the 
labour force is under 400. Above that number there is less 
chance of mistake ; for, to maintain a labour force in the F.M.S. 
at a steady figure something like 30 to 50 per cent, of the force 
must be recruited yearly ; and this means there are sufficient 
new non-immune labourers to keep the disease in full flame. 
While referring to the admission rates for malaria, I would 
remind the reader that, when malaria is controlled, or when 
labour becomes immune and new arrivals stop coming in, 
not only do the admissions for malaria fall, but so do the 
admissions for all other diseases. Diarrhcea and dysentery 
are so frequently merely the terminal symptoms of chronic 
malaria, that the control of malaria has a notable effect on 
the admissions (and deaths) from these two diseases. 

Deaths. — All towns tend to attract the sick and dying from 
the surrounding district ; we saw it in the town of Klang in 
1901 ; it occurs daily on a large scale in larger towns like 
Singapore, as Dr Finlayson showed from a careful analysis 
of the malaria cases in hospital. While it is generally easy 
to make the required correction for residence, when a patient 
is admitted to a hospital, it is more difficult to obtain correct 
information from those furnishing a death report. 

What has been said of the admissions for malaria and other 
diseases applies largely to the deaths both from malaria and 
other diseases. Many new arrivals lead to a rise in the 
admission rates and death rates of malaria, of diarrhcea and 
dysentery, and generally of other diseases. Similarly, when 
the new-comers have become immune, the death rate drops, 
and may deceive the observer. The death rates, like the 
admission rates, must be read in the light of the spleen rates. 

2 A 



340 ON STATISTICS 

Sometimes I think of the two, the death rates and the spleen 
rates, as "cross bearings" v/hich fix the health with greater 
accuracy than any other figures. In this book, I have used 
them more largely than any other figures, not because many 
other figures are not available, but because some selection 
must be made in a work of limited size ; and these two sets 
of figures, in my opinion, give the most accurate information. 

Apart from "rates" worked out on the population, the 
gross number of deaths varies with the seasonal prevalence 
of malaria, and presents a striking picture, to which I shall 
refer presently. 

Spleen Rates. — Of any single set of figures, the spleen rates 
appear to me to give, in practice, the most accurate idea of 
the amount of malaria in a place. The parasite rate makes 
so heavy a call on time, which in itself limits the number of 
observations the isolated tropical worker can make, that the 
spleen rate, based on a larger number of observations, is 
probably more accurate as a figure indicating the amount of 
malaria in a given population and locality. 

It is usual to examine the children under ten years of age ; 
but as few native children know their ages, the observer soon 
adopts a height and appearance standard which he almost 
unconsciously applies before beginning his examination. With 
a little practice, it is possible to examine the children almost 
as fast as they can walk past. My custom is to make the 
children pass from left to right ; I use both hands ; the left 
hand is placed below the ribs behind, and the right hand in 
front. The spleen, if enlarged, is then caught between the 
fingers of the two hands. This bimanual examination of the 
organ gives greater accuracy than an examination by one 
hand alone ; for even quite small spleens can be pressed 
forward by the left hand fingers against the fingers of the 
right hand, which, with practice, become expert at detecting 
any abnormal resistance in the splenic region. Only rarely 
is it necessary to lay a child on his back, in order to relax 
the abdominal muscles. With adults it is almost essential to 
make the examination with the patient lying flat. 

In making the examination in a country where a kala-azar 
does not exist, it must not be forgotten : — (i) That an enlarged 
spleen may persist for several years after a place has become 
non-malarial ; (2) that healthy children may have come quite 



SPLEEN RATES 341 

recently to a malarial place and diluted the spleen rate; 
(3) that children with enlarged spleen may come to a healthy 
place, the spleen rate of which is zero ; and (4) that healthy 
infants often have a palpable spleen. 

In practice these corrections are easily made ; and many 
instances have been given in previous chapters. Only a very 
unobservant observer will be misled. On one occasion I had 
separated the children with enlarged spleens from those 
with normal spleens, when I overheard a small boy among 
those with enlarged spleens say in Tamil, " We are the old 
ones — they are the new." He was mightily pleased with his 
discovery, which was, as I found, correct. 

In several places I have shown how quickly new children 
acquire enlarged spleen in very malarial localities, even when 
they are receiving quinine ; within two months quite a high 
percentage may have enlargement of the organ. It will be 
found, too, that those who have not spleens are those most 
likely to have "fever" at the time of the examination. For 
example, there may be ten children who have been four 
months on the estate ; seven will have enlarged spleen, and 
three will be suffering from " fever " ; as a matter of fact, 
these are the figures of an observation. 

Enlargement of the spleen indicates a certain degree of 
immunity to the "pyrexia" or "fever-producing toxin"; for, 
although these children are not suffering from " fever," in 
a high percentage their blood contains parasites. Where 
the malaria, as indicated by the spleen rate, is only 
moderate in amount, say from 20 to 40 per cent., it is mainly 
among the children with enlarged spleen that parasites are 
found. 

It was a planter, Mr Stevens of Pilmoor Estate, who first 
made me realise that enlarged spleen meant an approaching 
immunity. One day I was examining the children on his 
estate, and had picked out those with enlarged spleen, when 
he remarked that they were the children who were recover- 
ing from their malaria, and the others were still sick ; 
some indeed had " fever " at the time I saw them. Having 
had this pointed out to me, observations on other estates soon 
confirmed it. Later on, I found it had been known for the 
last 300 years. The manner of my rediscovering it was as 
follows : — 



342 ON STATISTICS 

When a medical student in 1894 I purchased a copy, in 
fair preservation, of 

THE 
WHOLE WORKS 

of that excellent Practical Physician 
DR. THOMAS SYDENHAM 

WHEREIN 
Not only the HISTORY and Cures of accute Difeafes are treated 
of, after a new and accurate Method : and also the fhorteft 
way of curing most Chronical Difeafes. 

The Tenth Edition 
Corrected from the original Latin by 

John Pechey, M.D. 
Of the College of Phyficians in London. 

LONDON 

Printed for W. Feales, at Rowe's Head the Corner of Effex-ftreet in 

the Strand ; R. Wellington, at the Dolphin and Crown without 

Temple-Bar ; J. Wellington ; A. Bettefworth and 

F. Clay, in truft for B. Wellington. 1734. 

The book is, of course, of fascinating interest. At the 
time I made an index, in which I find " Giving of Peruvian 
Bark, the best method " ; from which it would appear that 
300 years ago there was a quinine controversy. There are 
also items " Dropsy at the end of Ague," and " Hard belly 
in children." But I had, however, forgotten all these things ; 
nor were they recalled until, sometime after Mr Stevens 
had made his remark on the spleens in children, I referred 
to the book, or at least to Chapter V. "Of the AGUES 
in the years 1661, '62, '63, '64." 

Quinine, or rather Cinchona, Peruvian bark, or Jesuit's 
powder, had come into use in Europe about 1640 ; and although 
widely used, there was still doubt about the best method and 
time to give it. Sydenham appears to have had no certain 
cure for malaria. Speaking of the Agues in the Fall he says : — 

" But if there be any Man who knows how to ftop the 
Career of thefe Agues, either by a Method or a Spefick, he 
is certainly obliged to difcover a thing fo beneficial to 
Mankind ; but if he refufe to do it, he is neither a good 
citizen, nor a prudent Man ; for it does not become a good 



THE CURE OF QUARTANS 343 

Citizen to referve that for himfelf, which may be advantageous 
to Mankind ; neither is it the part of a prudent Man to 
deprive himfelf of that Bleffing he may reasonably expect 
from Heaven, if he makes it his bufinefs to promote the Good 
of the Publick ; and truly, Virtue and Wifdom are more 
valu'd by good Men, than either Riches or Honour." 

" But tho it is hard to cure Agues in the Fall, yet I will 
mention what I have found moft fuccefsful in the management 
of them." 

He warns against purging and bleeding, but recommends 
sweating ; then he goes on : — 

" As to the Cure of Quartans, I fuppofe every who is but 
little converfant in this Art, knows how unfuccefsful all the 
Methods have hitherto been, which are defigned for the Cure 
of them, except the Peruvian Bark, which indeed oftener ftops 
it than conquers it : for after it has ceafed a Fortnight or three 
Weeks, to the great advantage of the Patient, who having 
been feverely handled by it, has a little breathing time, it 
begins again afrefh, tormenting him as bad as ever ; and for 
the moft part, how often foever the Medicine be repeated, it 
requires a long time before it can be vanquifhed : yet I 
will mention what I have obferv'd concerning the Method 
of giving it. 

" But you muft take care not to give the Jesuits Powder 
too foon, before the difeafe has a little wafted itfelf, unlefs the 
weaknefs of the Patient requires it fhould be given fooner : 
... I think it better to tincture the Blood leifurely with the 
aforefaid Medicine, and a good while before the Fit, than to 
endeavour at once to hinder the Fit juft approaching, for by 
this means the Remedy has more time to perform its bufinefs 
thorowly, and then the Patient is freed from the danger that 
might happen by a fudden unfeafonable Stop, whereby we 
endeavour to fupprefs the Fit that is now about to exert it-felf 
with all its Might. Lastly, the Powder muft be repeated at 
fuch fhort diftances of Time, that the Virtue of the former 
Dofe be not quite fpent before the other be given : for by the 
frequent Repetition a good Habit of Body will be recover'd, 
and the difeafe wholly vanquifh'd." 

For the very young suffering from the spring and autumnal 
tertians, he says that bark may be used with good success, 
but he prefers to leave the whole - business to Nature. He does 
not recommend either change of air or diet: "for I never found 
hitherto any ill from thence, if the Bufinefs be wholly left to 



344 ON STATISTICS 

Nature, which I often observ'd with admiration efpecially in 
Infants." For the old he recommends a change of air to a 
warmer country, and cordials strengthening diet. 

In all probability malignant subtertian malaria did not 
exist in England and London in Sydenham's time, so he was 
able to withhold the powders from infants, and it was possible 
for patients to go on with their fevers for months on end. 
This gave him the opportunity of observing the natural course 
of the disease in more favourable conditions, from certain points 
of view, than obtains in the tropics. Anyhow he did observe 
the disease closely, and we find the following on prognosis : — 

" It is worth noting, That when thofe Autumnal Agues have 
a long time molefted Children, there is no hope of recovery 
till the Region of the Belly, efpecially about the Spleen begins 
to be harden'd and to fwell ; for the Ague goes gradually off 
as this Symptom comes on ; nor perhaps can you any other 
way better prognofticate the going off of the Difeafe in a fhort 
time, than by obferving this Symptom, and the fwelling of the 
Legs, which are fometimes feen in grown people." 

That describes pretty accurately what Mr Stevens dis- 
covered for himself and told me ; which reminds me that I 
am writing a chapter " On Statistics," and this is the section 
on Spleen Rates. 

In malarial places where the spleen rate is 50 or over, 
the systematic use of quinine does not appear to affect the 
rate appreciably ; but when malaria is less severe, or where 
the malarial season lasts only a few months, quinine does lower 
the spleen rate, as my old friend Major J. D. Graham, I. M.S., 
showed in 1914. 35 

The Seasonal Variation of Malaria. 

In Malaya, where the conditions are apparently so favour- 
able to mosquitoes throughout the whole year, one would hardly 
expect any marked seasonal variation in the malaria. Yet it 
is not so. It is true that the introduction of many non-immune 
people into a malarious place, at any time of the year, will 
forthwith be followed by a severe outbreak of malaria, showing, 
as we know, that there is usually a considerable number of 
active insects present (Fig. in). But apart from such 
accidental outbursts, there are definite seasonal variations, 
which form curves or waves varying with the species carrying 



SICK CHART 



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346 ON STATISTICS 

the disease. The subject has not been as fully worked out 
as it might have been, owing to the defective system of 
death registration in this country. We have, however, learned 
something. 

When, at the end of ic.oi,the figures of malaria from the 



Per 

Cent. 

30 


Jan. 
Feb. 
Mar. 
Apr, 

May 

June 

July 

Aug. 

Sept. 

Oct. 

Nou. 

Dec. 


29 




























28 


The Admissions for Malaria tc 
Kl'ang Hospital from 1893 tp 1900 










27 


exlpres|sed 
Total Adrr 


as al Percentage of th|e 










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rosu 


s 
















17 




























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FlG. 112. — Chart of the Admissions for Malaria to Klang Hospital from 1893 to 1900, 
expressed as a Percentage of the Total Admissions. The umbrosus Wave. 

hospitals of the three coast districts of Selangor were charted ; 
they showed notable differences. Whereas the malaria wave 
in Kuala Selangor district had reached its maximum in 1899, 
that in Klang still rose for two more years, and doubtless would 
have continued to rise but for the anti-malaria work done, for 
the population was rapidly increasing. 

But there was another difference : this time between the 



MALARIA CURVE 



347 



Klang and Kuala Selangor charts on the one hand, and the 
Kuala Langat chart on the other. In the Klang chart there 
was generally a steady increase of malaria throughout the year 
from the minimum in February to the maximum in October, with 
slight pause in August. Fig. 112 chart represents the average 
of the percentages of malaria treated each month from 1893 to 
1900. (The percentages are averaged so that the larger totals 
of the later years may not dominate the results unduly). The 
Kuala Langat chart, which in reality represented only the 
sickness of the inhabitants near to Jugra Hill, showed a 
sharp rise about April or May, when the maximum might 
be reached, and the epidemic as sharply subsiding in August, 
September, or October ; which was quite a different figure from 
that of Klang District. 

It was not until later that the significance of these differences 
came to be understood ; and this is the explanation. 

The curve with the maximum in November — the Klang 
chart — is due to malaria caused by A. umbrosus, and possibly 
other pool breeders. It is unlikely that A. maciilatus affected 
it in these years. The other curve with the wave in the centre 
months of the year — from April to September — is the malaria of 
A. maculatus in hill land. The larvae of A. maculatus are greatly 
reduced in number by the heavy rains of November, December, 
and January ; but in the two drier months, February and March, 
they appear in enormous numbers. Shortly afterwards the 
malaria wave appears. Fig. 113 shows the monthly admissions 
for malaria of three hill land estates situated a few miles 
apart ; the general similarity of the waves is striking ; and I 
may add that the rise of the wave took place not merely in the 
month of April, but almost in the same week of the month, 
as the following table shows :— 



Weekly Admissions for 


Malaria. 




1910. 


Estate "A." 


Estate "B." 


Estate "C." 


Week ending 25th March . 
„ 1st April 
„ 8th April 
„ 15th April . 
„ 23rd April . 


13 
16 
21 

25 
43 


10 

4 
12 

38 
39 


5 

7 

6 

36 

22 



An attempt is now made to abort this wave by special 



348 



ON STATISTICS 





Jan. 

Feb. 

Mar. 

Apr. 

May 

June 

July 

Aug. 

Sept. 

Oct. 

Nov. 

Uec. 


190 
180 










1 

ii 
■ i 
















170 










i i 
i i 
i , 


The Curve of Malaria 








160 










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from Anopheles 


Macula 


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Fig. 113. 



MALARIA CURVE 349 

attention to oiling between February and June, and particularly 
in the drier periods of these months. Good results appear to 
be obtained. 

Where part of the area is flat and part hilly, the annual 
statistical curve is, of course, a combination of the two waves. 



CHAPTER XXIX 

RESULTS 

In the preceding pages many instances of the control or 
partial control of malaria have been given ; and it has been 
possible to associate directly the improved health with its 
cause, namely, some form of anti-malarial measure ; it may 
have been open drainage, subsoil drainage, oiling, removal of 
people from the vicinity of jungle, or of jungle from people, 
or only the preservation of jungle. The number of people 
affected by any single operation has usually been small — 
perhaps only a few hundreds, although in places it has been 
greater. The sum total of the people is, however, considerable ; 
so it may be worth gathering together the threads to see what 
manner of pattern they make. 

Towns of Klang and Port Swettenham. 

The only figures in my possession are those already given 
in the earlier part of the book. 



Table showing 


Deaths in the two Tmvns 


corrected for Deaths 


Year. 


occurring in the Hospital. 


Deaths 


I900 
I90I 
I902 

I903 
1904 






474 
582 

144 
"5 
122 


1905 






"3 



The anti-malarial work was begun in 1901 ; and the figures 
indicate that from 1902 onwards, several hundred lives have 
been saved annually. In 1901 the population was only 3576 
for the two towns ; but they have never ceased to expand. 
To-day, as determined by the recent food control census, the 
population of the town of Klang is over 20,000 people, and 

350 



ESTATES UNDER THE AUTHOR'S CARE 351 

that of Port Swettenham nearly 6000. Can anyone doubt 
that had the anti-malarial work not been done originally in 
1901, and subsequently extended to cover the new population 
in the enlarged towns, many lives would have been lost 
annually, which, in fact, have been saved. In the eighteen 
years many thousands of lives must have been saved in the 
two towns. 

Estates under the Author's Care. 

Figures are available of the health of the labour forces 
under my care. The estate hospital system was started in 
1908 ; but my connection with the estates and researches into 
the causes of their ill-health began before that — at a time, 
indeed, when a healthy estate was practically unknown. 

The following figures are taken from the Official Returns 
printed in the Annual Indian Immigration Reports, except 
for the year 1919, which are compiled from the monthly 
returns sent to the Health Department. The Immigration 
Report for 1919 has not yet been published. 



Year. 


Labour Force. 


No. of Deaths. 


Deatli Rates per 1000. 


1906 


9,939 


528 


53-1 


1907 


13,676 


707 


5i-7 


1908 


15,898 


1053 


66-2 


1909 


16,982 


527 


31-3 


1910 


23,295 


"55 


49-5 


19II 


29,567 


1924 


6 5 -i 


I912 


32,394 


1017 


3i-4 


1913 


38,248 


975 


25-4 


1914 


34,040 


882 


25-9 


1915 


30,456 


572 


19-0 


1916 


31,877 


666 


20-8 


1917 


28,954 


664 


22-9 


1918 


28,227 


1269 


44-9 


1919 


27,030 


478 


17.9 



The figures and the chart show an almost continuous 
improvement in health ; and further improvement may be 
expected if the recommendations made are efficiently carried 
out, and the work already done maintained and extended.* 

The improvement was checked, however, on several notable 

occasions. In 191 1 about 30 per cent, of the deaths were 

probably due to the breakdown in the Penang Quarantine 

Station ; of some 10,000 coolies in it many suffered from 

* The death rate for 1920 was 17-5 per mille. 



352 RESULTS 

cholera, dysentery, and malaria ; many died in the station ; 
and many others died soon after their arrival on the estates, 
and so raised the death rate. In 1916-1917 a severe local 
outbreak of malaria almost doubled the death rate of the 
Kapar District. It was mainly due to the new railway — as I 
have described in the section entitled The Story of a Coast 
Railway — in Chapter XXII. 





OOOQmmmihihmmihmm 


70 
—60 

—50 





-£40 

oa 

3 
Q= 

-£•30 

a 

—20 

— 10 













































































- 













































































































































FIG. 114. — Chart of Death Rates of Labour Force under my care. 



In 1918 the world-wide epidemic of influenza affected the 
estates. In 1919 the disease was still haunting the coolie 
ships, and affected many coolies both in the quarantine station 
and on the estates. Despite this and the shortage of rice, 
the death rate for 1919 is the lowest on record. 

Had the death rate remained at 66-2 — the figures for the 
year 1908 — the number of deaths occurring annually would 



THE ESTATE LABOUR FORCE OF THE F.M.S. 353 

have been as shown in the following table. The table also 
shows the number of lives presumably saved. 



Year. 


Labour Force. 


No. of Deaths 
that occurred. 


No. of Deaths 
at the rate of 
66'2 per mille. 


Estimated 

No. of Lives 

Saved. 


1908 
1909 
1910 
1911 
1912 

1913 
1914 
1915 
1916 
1917 
1918 
1919 

Total . 


15,898 
16,982 
23,295 
29,567 
32,394 
38,248 
34,040 
30,456 
31,877 
28,954 
28,227 
27,030 


1053 
527 

"55 
1920 
1017 

975 
882 
572 
666 
664 
1269 
478 


1221 

1537 
1951 

2137 
2524 
2246 
20IO 
2I03 
igiO 
1862 
1783 


694 

372 

31 

1 1 20 

1549 
1364 
1438 
1437 
I246 
393 
1305 








10,949 



Large as the saving of life has been according to this 
calculation, there is reason to believe that it is an under- 
estimate ; for we have seen that to increase the number of 
non-immune people in a malarial area increases the death 
rate at an ever - accelerating rate until it reaches 300 per 
mille * or over. The large increase of the population since 
1908 would, therefore, have led to a death rate far in excess 
of the rate 66-2 on which the calculation is based ; and the 
saving of 10,949 may be regarded as well within the truth. 

The years have shown how even in a country notorious 
for its ill-health and high death rates, large, healthy, and 
prosperous labour forces can be built up out of very un- 
promising material: for the Indians who come here are usually 
poverty-stricken, often half-starved, and possess little resistance 
to disease. 

The Estate Labour Force of the F.M.S. 

Although ten years ago the control of malaria in rural 
districts was not considered practicable, and even to-day one 
hears talk of the almost insuperable difficulty and extravagant 
cost hardly making " the game worth the candle," that has 

* General Gorgas claims that 71,370 lives were saved by sanitary work 
in Panama during the construction of the Canal, and calculated this from 
the French death rate of 200 per mille. 



354 RESULTS 

not been the attitude generally adopted in the F.M.S. On 
the flat land, the cost was often nothing ; for a healthy site 
was selected instead of an unhealthy one, and the choice cost 
nothing. To quote the report of the Senior Health Officer 
for the year 191 5 : — 

" Upon estates situated in the alluvial flats of the Coast 
Districts of Krian, Lower Perak, and Selangor, the health of 
the labourers is excellent, the only cause for anxiety is lack 
of good water in times of drought. . . ." 

Of hill land he says : — 

" Anti-malarial measures of various sorts are universal upon 
most up-country estates, the most common is the prophylactic 
administration of quinine, many estates now spray with oil 
all swamps and ravines adjacent to the coolie lines, and a few 
have expended large sums on subsoil drainage. 

" Labourers are now generally housed in well-constructed 
lines built upon open clearings which afford good drainage ; 
these have replaced the dark palm-leaf hovels on the edges of 
swamps or ravines, and closely surrounded by jungle or rubber 
which were formerly so common." 



Death Rate per Milk of Estate Labourers in the Federated 
Malay States. 



Year. 


All Nationalities. 


Indian Labourers. 


Number. 


Death Rate. 


Number. 


Death Rate. 


1906 






24,225 


57-8 


1907 






36,092 


55'7 


1908 






4S.5H 


68-6 


1909 






49,924 


46-8 


1910 






73,H7 


43-8 


igil 


143,614 


62.9 


110,000 


65-1 


1912 


171,968 


41-0 


122,000 


41-0 


1913 


188,937 


29.6 


133,072 


30-4 


1914 


176,226 


26.3 


128,506 


28-7 


1915 


169,100 


16-7 


120,190 


20-9 


1916 


187,030 


17.6 


129,964 


22.0 


1917 


214,972 


18. 1 


140,346 


22-4 


1918 


2I3,4 2 3 


42-5 


144,716 


53-8 


1919 


237,128 


14-6 


160,657 


18.6 



Improved water-supplies, increased and improved hospital 
accommodation, etc., have been provided for labourers, all of 
which have contributed to the lowering of the death rate ; and 
it is impossible, from the data available, to disentangle the 



SINGAPORE 355 

part due solely to the anti-malaria work, important though 
it must be. So I have contented myself with giving simply the 
death rate of the labour force in the F.M.S. since 191 1. Each 
year measures to improve health become more efficient, and 
without doubt further improvement will take place. 

From 1906 to 1910, the figures for the Indian labourers 
include the indentured labour. There are no official statistics 
of estate labour other than Indian prior to 191 1. 

Taking the death rate of 62-9 per mille, and calculating as 
in the previous table, the number of lives saved from 191 1 to 
1919 is 58,102. 

In this calculation no account is taken of the lives saved 
before 191 1 in the F.M.S. ; nor have I reckoned the saving of 
life by similar work elsewhere in the Peninsula ; in the Settle- 
ments of Malacca, Province Wellesley, The Dindings ; or in the 
Unfederated Malay States, like Johore and Kedah. In these 
areas there are many thousands of estate labourers ; on many 
occasions I have visited estates to advise on sanitary measures; 
and to my knowledge much excellent work is being done, and 
many lives saved. Of the work done in the city of Singapore, 
the chief city of Malaya, I will speak presently. 

These results have been achieved not in a specially selected 
body of recruits, but among the poorest classes of India 
and China. The Indians, in particular, often arrive in the 
last stages of destitution, with hardly a rag of clothing for 
the adults, and none at all for even large children. The 
famines, which for ages have swept that land, have left their 
mark in the poor physique of the Tamils of Southern India ; 
and even to-day famine drives whole families, of two or three 
generations, to Malaya. Many of the very old people are on 
the labour rolls, for occasionally they do a little light work ; 
among these, as well as the infants, malaria has a deadly 
effect. 

Great as the improvement in health has been, much still 
remains to be done ; more estates can be made fit for Indian 
labour than now employ it ; and the death rate of all can, 
I believe, be brought below 10 per mille. 

Singapore. 

The City of Singapore, placed by the foresight of Raffles 
one hundred years ago on the great highway to the East, has a 

2 B 



356 RESULTS 

population to-day of over 300,000 people. Even twenty years 
ago, as reckoned by the tonnage of the shipping, it was the 
seventh largest port in the world. 

The entrepot of the Great Archipelago and the neighbour- 
ing lands, it contains a curiously mixed population from East 
and West, from North and South ; the main constituents of 
which are Chinese, Indians, and Malays. Arriving yearly by 
thousands, or passing through on their several ways to work 
in the surrounding countries and islands, such a population 
places peculiar responsibilities on the Health Department, and 
has made its work specially arduous. Back lanes, insanitary 
houses, food and markets, lodging-houses, slaughter-houses, 
offensive trades, hawkers, and many other things demanding 
the activities associated with a Health Department in a large 
city had kept the staff busy ; vast improvements had been 
affected ; yet the death rate remained obstinately high. Great 
waves of malaria from time to time swept the city, reaching in 
June 191 1 a maximum of 85-83 per mille. They defied every 
effort of the Department, and seemed to render fruitless almost 
all its work. 

In 191 1, malaria control was a much discussed subject. 
Many authorities were far from optimistic about the result 
of anti-mosquito work. In an able report the Health Officer, 
Dr W. R. C. Middleton, reviewed the whole subject ; and 
subsequently, at his suggestion, and on the invitation of the 
Anti-malaria Committee, I visited Singapore and made recom- 
mendations for dealing with the most malarial district. 

The work was admirably executed ; it led to a rapid and 
permanent fall in the spleen rate ; and since then it has been 
widely extended, although some areas remain to be done. 

In such a shifting population, where, from inquiry, 30 to 50 
per cent, of the hospital malaria admissions have been shown 
to be imported from beyond the city limits, the unravelling of 
death rates and an estimate of the effect of the anti-malaria 
work may appear a mere juggling with figures. Yet I think 
it is not so ; for much information can be gained by a study of 
the monthly and annual variation of the death rates, which I 
have printed in the appendix. 

The outstanding fact is a great fall in the death rates since 
the anti-malarial work was begun in 1911, when compared with 
those of the previous twenty years. 



SINGAPORE 

Death Rates of Singapore. 

1892 to 191 1 average death rate 

1912 to 1919 „ „ . . 

Difference 



357 



Per mille. 
42-33 
3478 

7-55 



If the average population between 1912 and 1919 be taken 
roughly as 280,000, the number of lives saved by all sanitary 
measures in Singapore in these eight years is 2100x8 or 
16,800. What share of this is to be credited to the malaria 
control work ? 

Another outstanding fact, when we consider the figures, is 
the great rise in the death rates in the middle months of the 
year, usually beginning in May. Between 1901 and 191 1 it 
occurs every year, with the exception of 1906 ; and in most 
years forms the curve, with which the reader must now be 
familiar, of malaria caused by A. maculatus, a mosquito, as 
Dr Hunter proves, prevalent and of importance in Singapore. 
To show how serious these waves were, the following table 
shows the highest monthly rise between 1901 and 191 1 (cholera 
and smallpox are excluded). 

Of the eleven years : — 

In 1 1 the monthly rate rose above 40 per mille. 

45 
5° 



10 
9 

5 
3 



55 
60 
70 
80 



Now if malaria control played any important part in the 
lowering of the general death rate, it would be reasonable to 
expect a reduction, if not the obliteration, of the annual 
malarial wave. The anti-malarial work was begun in 191 1, 
and subsequently we do find a reduction in the magnitude of 
the malaria wave (cholera and smallpox are included). 
In 1912 the wave rose to 56 per mille. 



1913 


)> )) 


42 


1914 


)) )> 


42 


1915 


)■> )1 


28 


1916 


») )) 


36 


1917 


J> )J 


39 


1918 


)) )) 


68 


1919 


* Influenza. 


33 



358 



RESULTS 



To sum up: whereas prior to 191 1 it was almost normal 
for the wave of malaria to sweep the death rate above, and 
often far above, 45 per mille, the wave has only reached that 
figure once — the influenza year is excepted — since the anti- 
malarial work was begun. As long as anopheles breeding- 
places exist in Singapore, and men who contract malaria 
elsewhere come into the city when ill, so long will the 
mortality rates show an upward curve in the malarial season. 
But when we recall the evidence given in the preceding chapters 



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50 






















n 


















48 








































46 






- 1 
































44 






u 






















































J 

* 


1892-1911 > 


'ver 


xge 


42-33 


































40 








































38 




































3 




36 




































u> 




34 
















Aut 


rag 


































32 








































30 








































28 






CI 


TV 


' 


F 


SI 


NC 


rAPOl 


*B 
















26 






An 


1U2 


1 I 


)eath 


Rate: 


















24 

















































































Fig. 11 5.— Chart of the Death Rates of the City of Singapore. 

of this book — of malaria control, its seasonal waves, its effects 
on special and general death rates, the relationship of death 
rates and spleen rates — and then consider the lowering of the 
general death rate, the flattening of the mortality curve, and 
the fall in the spleen rate of Singapore, it seems to me we 
are irresistibly drawn to the conclusion that, more than any 
other factor, the anti-malarial work of the past eight years 
has led to the improved health of the city, and contributed 
to the saving of over 16,000 lives. 

Yet, whatever the cause or complex of causes may be, 



PANAMA 359 

which has lowered the death rate, the saving of thousands of 
lives is a fact beyond dispute, and one in which the Health 
Officers of Singapore may take a legitimate pride. It is, 
indeed, a splendid example of Preventive Medicine in the 
Tropics, and an inspiration for the great and difficult tasks 
that still lie before them. 



There is a considerable mass of evidence to show that in 
the past twenty years, sanitary work generally, and particularly 
the control of malaria in conjunction with other measures, has 
saved 100,000 lives in the Malay Peninsula, and an enormous, 
but incalculable, amount of money. 



Panama. 

Critics of the work done by the Americans in Panama 
sometimes say that what was accomplished there would be 
impossible under less special conditions. They contend that 
the canal was built primarily as a war measure to safeguard 
the interests of Americans ; cost was of minor importance, 
and the work was backed by the whole assets of the United 
States Treasury. They point out that the area dealt with 
was only 50 square miles, and declare that the population 
was under an iron discipline not attainable in other countries. 

These criticisms may, or may not, be strictly true ; but, 
if true, they are answered, I think, by the work done in 
the Malay Peninsula. Here the work has been done by 
Government in the ordinary course of its sanitary administra- 
tion ; and by the Estates, which are commercial undertakings, 
whose policy is influenced by price of the produce they sell. 
The area of the operations extends to thousands of square miles ; 
indeed the area over which the estates under my supervision 
are scattered is more than 1000 square miles. The population 
of the estates is under a certain amount of discipline ; but, 
the labour being free and not indentured, the discipline is 
far from being of the military variety. 

In Malaya, the control of malaria has been attempted 
successfully under many different conditions ; from small rural 
populations of two or three hundred people on estates, and 
in small towns of three or four thousand inhabitants like Klang j 



360 RESULTS 

to a city like Singapore, with over a quarter of a million people ; 
the complexity of the entomological aspect of the problem, 
from the number of species carrying malaria under different 
conditions, has no parallel in Panama; the number of lives 
already saved by the work annually is greater in Malaya than 
in the Isthmus ; and I might add that the work was begun here 
some years before it was started there. 

The work in Panama is, in my opinion, without question 
the most brilliant achievement in Preventive Medicine which 
the tropics, and for that matter the whole world, has seen; 
but such a statement in no wise detracts from the value of what 
has been accomplished in Malaya. The work in the two 
places may be compared to the advantage or disadvantage 
of either, as the critic may be biassed. In truth, they are to 
be regarded as complementary; each developing on the lines 
best calculated to achieve its object in its own peculiar circum- 
stances. They represent different phases or stages in progress 
towards the time when man shall conquer the tropics by 
stamping out its diseases ; and these rich lands, many of the 
most fertile on the face of the earth, shall pour out, in unstinted 
measure, of their abundance for the welfare of the human race. 



CHAPTER XXX 

CONCLUSIONS 
The conclusions I draw from these observations are : — ■ 

Mosquito Reduction. 

(i) From a malarial standpoint, the Malay Peninsula can 
be divided into several zones which may conveniently be 
distinguished as, the Mangrove Zone, the Coastal Plain, the 
Coastal Hills, the Inland Plain, and the Inland Hills. 

(2) These zones may be malarial naturally, or may become 
so through the operations of man. 

(3) The part of the Mangrove Zone covered daily by the 
tide contains no anopheles and is non-malarial. When the 
forest is felled and the tidal flow obstructed, it may 
become intensely malarial from the appearance of A. ludlowi, 
which has been proved to be a natural carrier of malaria 
and is probably the most important carrier in the Mangrove 
Zones. 

(4) The part of the Mangrove Zone covered only by the 
spring tides is naturally malarial from the presence of A. 
umbrosus, which has been proved to be a natural carrier of 
malaria. Clearing the forest allows A. ludlowi to enter this 
portion of the zone also. 

(5) Both A. ludlowi and A. umbrosus are eliminated by 
clean weeded drains and good drainage ; and many examples 
of how good agriculture abolished these mosquitoes and their 
malaria from the Mangrove Zone can be given. 

(6) The Coastal Plain is malarial from the presence of 
A, umbrosus in its virgin jungle. 

(7) Hundreds of square miles of flat land in the Coastal 
Plain of Malaya have been freed from malaria by simply drain- 
ing and felling the jungle, and cultivating the land. 



3G2 CONCLUSIONS 

(8) The disappearance of malaria from the Coastal Plain 
coincides with the disappearance of A. umbrosus, which breeds 
in pools in undrained jungle, but cannot breed in open earth 
drains when kept free from weeds, and with a current of water. 
There are probably other reasons connected with the quality of 
the water in well-drained land. 

(9) Ten years ago the cost of these rural anti-malaria 
measures in Malaya was about £3 sterling an acre, being 
£2 to drain, and £1 to fell the heavy virgin jungle. This 
expenditure is, at the same time, the first step in agriculture, 
and the land has then acquired a considerably increased value. 
To-day the cost of draining and felling is about 70 per cent, 
higher. When an estate is newly opened, it is possible for the 
Medical Officer to select non-malarial sites, and the cost of 
controlling malaria is, of course — nil. 

(10) In the low Coastal Hills next to the Coastal Plain, 
malaria is prevalent when the ravines are under jungle owing 
to the presence of A. umbrosus in large numbers. 

(11) Clearing and draining of these ravines frees them from 
A. umbrosus, but does not free the land from malaria. 

(12) Malaria persists in the Coastal Hills after the ravines 
have been cleared and drained and after A. umbrosus has 
disappeared, from the appearance of A. maculatus. 

(13) A. maculatus does not live in ravines covered by heavy 
jungle ; but appears only after the shade has been removed. 
The cleaner the water, and the better drained the ravine, the 
more suitable the ravine becomes for A. maculatus. 

(14) The utmost care and cleanliness from an agricultural 
point of view continued over a period of years, fails to eliminate 
A. maculatus and its malaria. 

(15) A. maculatus can be completely abolished from ravines 
by subsoil drainage, or spraying with suitable oils : and its 
malaria disappears with it. 

(16) The Inland Plains are poorly represented in Malaya. 
They are healthy like the Coastal Plains when opened ; but 
A. aconitus, if present in streams of running water, must be 
controlled. 

(17) The Inland Hills are non-malarial when under virgin 
jungle, because A. umbrosus does not exist in the ravines. 
They differ in this respect from the Coastal Hills. 



RICE FIELDS— QUININE 363 

(18) The Inland Hills become intensely malarial when the 
ravines are opened, because A. maculatus appears. In this 
respect they are like the Coastal Hills. 

(19) Subsoil drainage, and oiling which control A. maculatus 
in the Coastal Hills are equally suitable in the Inland Hills. 
In the future it will probably be found more economical in 
many places to allow the ravines to revert to jungle. In 
opening land in this zone in the future, malaria can be avoided 
by refraining from felling the jungle in the ravines. This will 
cost nothing. 

Rice Fields. 

(20) Rice fields on the Coastal Plain are practically free 
from malaria. The anopheles found are A. rossi, A. kochi, 
A. sinensis, A. barbirostris , and maybe A. fuliginosus. 

(21) Rice fields in narrow valleys are usually, in my 
experience, malarial. The anopheles found are A. rossi, A. 
kochi, A. sinensis, A. barbirostris, A. fuliginosus, and A. aconitus 
has been proved a natural carrier of malaria. 

(22) Further research will almost certainly show how the 
malaria of rice fields in valleys can be controlled by altering 
the composition of the water — by polluting it ; which will be 
a great boon not only to the Malays, who cultivate the rice, 
but to others, by increasing the food production of the country. 

Quinine. 

(23) Quinine given regularly reduces the sick rate and 
death rate of those exposed to malaria. 

(24) Doses of less than 6 grains daily are of little value 
where malaria is intense — say where the spleen rate is over 60. 

(25) Where malaria is intense, and the population consists 
of immigrants, take 10-grain doses on six days out of the 
seven, and 20 -grain doses when suffering from pyrexia or 
not at work on account of ill-health, between 20 and 30 per 
cent, of those taking the drug will be found with parasites in 
their peripheral blood. 

(26) The use of quinine can, therefore, never result in the 
abolition of malaria, nor make any material reduction in the 
liability to infection in an intensely malarial locality. 



364 CONCLUSIONS 

(27) In twenty years'' experience I have seen quinine given 
systematically for long periods in many intensely malarial 
places ; but in no place have I seen any material reduction in 
liability to infection due to quinine alone ; most newcomers 
have become infected, and have died or become immune. 

(28) Quinine systematically given probably assists the 
infected to acquire a natural immunity. Where there is no 
re-infection ten to twenty grains in solution for three months 
is an almost certain cure for the people of most races — 
Malayalees appear to be an exception. Rest in bed on four 
successive Sundays assists quinine to stop relapses. In women 
there is a special necessity for quinine at menstrual periods. 
Abortion and the very fatal malarial anaemia of pregnancy 
can often be prevented by the continuous use of quinine in 
doses of from ten to twenty grains daily throughout pregnancy. 
Abortion is produced, not by the quinine, but by the malaria. 

Screening. 

(29) The attempt to discover a satisfactory screened coolie 
line ended in an inconclusive experiment, as I was unable 
to supervise it to its termination. 

(30) Screened bungalows for Europeans have proved of 
great value. 

(31) Screened hospitals give a real protection in patients; 
mosquito curtains in hospitals for Asiatics are practically value- 
less, and are more expensive than screening. 

The Labour Problem. 

Much is said about the difficulty there will be in the future 
of obtaining labour for F.M.S. It is stated that the F.M.S. 
will never be able to attract from India all the coolies required, 
and that the estates will have to depend on Chinese labourers. 

I confess I am an optimist on this subject, and have no 
fear for the future, if a wise medical policy be adopted by 
this country. For a number of years now, I have watched 
many estates ; and as a result have come to these conclusions. 

(32) Until the recent difficulties with shortage of rice 
and adverse Indian exchange, few healthy estates have failed 
to obtain all the coolies required ; some years there may be 



THE LABOUR PROBLEM 365 

shortage, but in most years more are recruited than are required. 
This applies not only to old estates, but also to new estates 
like " EE," which in its third year imported more labour from 
India than any other estate in the F.M.S. The chief difficulty 
of healthy estates is the prevention of crimping ; that is, 
having their coolies enticed away by unhealthy estates. 

(33) Unhealthy estates are perfectly well known to the 
coolies both here and in India, and are generally avoided ; 
not only have these estates difficulty in obtaining labour, but 
the annual loss of labour through death, discharge, etc., is 
30 to 50 per cent, greater that on the healthy estates. 

(34) Chinese labour, being originally non-immune to malaria, 
suffers almost as much as Indian labour, when living perman- 
ently on the estate like Indian labour. It is only when the 
Chinese labourer can leave the estate when ill, that he survives 
to resume his work another day ; he gradually acquires a 
natural immunity. 

(35) Chinese know which estates are unhealthy; and the 
wages paid on unhealthy estates to Chinese are much higher 
than those paid to Tamils on healthy estates. 

(36) Healthy estates are not without interest in all others 
becoming healthy, since the unhealthy estates, by their attraction 
of higher wages, unsettle the coolies of the healthy estates and 
often attract their skilled tappers. 

(37) Were all estates healthy, more Indian labour would 
be attracted ; it would be more efficient ; and there would 
be more inducement for the coolies to make the F.M.S. 
their home. 

(38) Were the country inhabited by the Malays, and more 
particularly the rice-fields of valleys, made healthy, the Malay 
infantile death rate would be greatly reduced, and an abundant 
healthy Malay population supported by their rice-fields would 
come into being. Java is a wonderful example of how a Malay 
race can expand. 

(39) In this way, even apart from the Chinese, this naturally 
rich country would obtain the labour force without which its 
development is impossible, " and I believe," as I wrote ten 
years ago, " that the labour problem is nothing but the malaria 
problem, and that the solution of the malaria problem will also 
be the solution of the labour problem. No estate can ever 



366 CONCLUSIONS 

have an assured labour force where the women wail, ' We cannot 
have children here, and the children we bring with us die.' 
Such is the cry on the unhealthy estates : ' It is vain to contend 
with the instinct of her who weeps for her children and will not 
be comforted.' It is because I believe we do now know how 
to save the children that I am an optimist for Malaya. This 
volume has shown how malaria has been driven from great 
tracts of country, and how the development of the country 
under the British has been a boon, not only to the native but 
to the foreigner also. Already irrigation and drainage have 
not only assured them of their crops, and given them wealth 
beyond anything they had known, but have given them freedom 
from their most deadly disease over wide areas. It remains 
but to extend these benefits. And although some details have 
still to be learned, I think that working on Ross's discovery, and 
on the method advocated by him, we may confidently hope to 
drive the disease completely from the land." 



REFERENCES. 

1. Belfield. Handbook of the Federated Malay States. 

2. Ross. The Prevention of Malaria. 

3. Manson. Brit. Med. Journ., 29th Sept. 1900. 

4. Grassi. Brit. Med. Journ., Oct. 1900, p. 1051. 

5. Koch. "German Malaria Commission," Brit. Med. Journ., Sept. 1900. 

6. Reports to the Malaria Committee of the Royal Society. 

7. Leicester. Studies from the Institute for Medical Research, vol. iii. 

8. Watson. Journ. of Tropical Med., Nov. and Dec. 1903. 

9. Watson. " Report on Drainage of Country Roads," Selangor Govern- 

ment Gazette, 1904. 

10. Watson. "Some Clinical Features of Quartan Malaria," Journ. 

Malaya Br. of B.M.A. and l.M. Gazette, 1905. 

11. Ludlow, (a) The Mosquitoes of the Philippine Islands ; the Distribu- 

tion of Certain Species, and their Occurrence in Relation to the 
Incidence of Certain Diseases, 1908. 

(b) Disease-bearing Mosquitoes of North and Central America, 
the West Indies, and the Philippine Islands, 1914. 

12. Ludlow. Ibid. (a). 

13. De Vogel. Myzomyia rossii as a Malaria Carrier, Semarang, 1909. 
De VOGEL. "Anophelines dans l'eau de mer," Soc. Stud. d. malaria, 

1906. 

14. MANGKOEWINOTO. "Anophelines of West Java," Meded. Burgerlijken 

Geneesk. Dienst in Ned. Indie., Deel ii., 1919. 

15. Christophers. "Malaria in the Andamans," Scien. Memoirs, New 

Series, No. 56, 191 2. 

16. De Vogel. "Report of the Investigations carried out with Regard to 

the Sanitary Condition of the Port Sibolga," Meded. Burgerlijken 
Geneesk. Dienst in Ned. Indie., Deel iv., 1915. 

17. Swellengrebel and Others. "The Susceptibility of Anophelines 

to Malaria Infections in Netherlands Indie" and "On the Biology 
of M. ludlowi in Sumatra," Meded. Burgerlijken Geneesk. Dienst in 
Ned. Indie., Deel iii., 1919. 

18. Watson. "The Effect of Drainage and other Measures on the Malaria 

of Klang, 7 M.S.," Journ. Trop. Med., 1903. 

19. Christophers and BENTLEY. Trans. Bombay Medical Congress, 1908. 

367 



368 REFERENCES 

20. Daniels. Brit. Med. Journ., 18th Sept. 1909. 

21. Ross. Brit. Med. Journ., Jan. 1920. 

22. GORGAS. Sanitation in Panama. 

Le Prince and Orenstein. Mosquito Control in Panama. 
Watson. Rural Sanitation in the Tropics. 

23. Daniels. Journ. Malaya Br. B.M.A., 1905. 

24. Watson. Malay Mail, 21st June 1910. 

25. Strickland. Certain Observations on the Epidemiology of Malarial 

Fever in the Malay Peninsula (see p. 29). 

26. Hall. The Soil. 

27. The reader may consult the following works for further information : — 

(a) SCOTT. Draining and Emba?iking. 

(6) King. Irrigation and Drainage. 

(c) Wheeler. The Drainage of Fens and Low Lands. 

{d) Davis and Wilson. Irrigation Engineering. 

28. Theobald. " A Monograph of the Culicidae or Mosquitoes." 
Howard, Dyer, and Knab. The Mosquitoes of North and Central 

America and the West Indies. 
Alcock. Entomology for Medical Officers. 
Swellengrebel. De Anophelinen van Nederlandsch Oost-lndic. Kol. 

Inst-te Amsterdam. 

29. Strickland. 

1913. (a) " Revision of the List of Malayan Anophelines," Ind. 

Journ. of Med. Res. 
(6) "The Myzorhynchus Group of Anopheline Mosquitoes in 

Malaya," Bull. Ento. Research, 
(c) "Short Key to the Anopheline Mosquitoes of Malaya, 

F.M.S.," Govt. Printing Dept. 

1914. (d) "Description of the Larva of Lophoscelomyia asiatica," 

Parasitology, 
(e) " Comparative Morphology of the A. ludlowi and rossi," 

Bull. Ento. Research. 
(/) " Notes on A. brevipalpis, Roper," Ind. Journ. of Med. 

Research, 
(g) " Short Key to the Larva? of the Common Anophelines 

of Malaya," F.M.S. Survey Office. 
1916. (h) "An Outbreak of Malarial Fever at Morib," Parasitology, 

January. 
(/') "The Epidemiology of Malarial Fever in the Malay 

Peninsula," Proc. of Federal Council, Nov. 1916. 
(/) "Description of a New Protanopheline Myzorhynchus 

hunteri," Ind. Journ. of Med. Research, 
{k) " Description of a New Species of Anopheline— novum- 

brosus," Ind. Journ. of Med. Research. 
(;«) " Note on a New Species of Anopheline— Myzorhynchus 

similis," Ind. Journ. of Med. Research. 



REFERENCES 369 

30. Stanton, (a) "The Larva of Malayan Anopheles," Bull. Enlo. 

Research, Sept. 1915. 

(b) " Notes on Sumatra Culicidas," hid. Journ. of Med. Research, 
Oct. 1915. 

(c) "A New Anopheline Mosquito from Sumatra, 1 ' Bull. Enlo. 
Research, March 191 5. 

31. Barbour. "Some Observations and Experiments on Malayan 

Anopheles, with Special Reference to the Transmission of Malaria," 
Phil. Journ. of Science, 19 18. 

32. Hacker. Malaria Bureau Reports, F.M.S., vol. i., 1919. 

33. The following works may be consulted : — 

West. Alga. 

Annandale. Fauna of the Inle Lake — in Records of the Indian 

Museum, vol. xiv., 1918. 
Annandale. The Fauna of British India — Fresh-water Sponges, 

Hydroids, and Polyzoa. 
MlALL. Aquatic Insects. 
Harrison and Aiyer. The Gases of Swamp Rice Soils in Mem. 

of Dept. of Agriculture in India. 

34. SIMM. " Sub-drainage as Applied to the Anti-malarial Campaign 

on the Isthmus of Panama," Ann. Trop. Med. and Hyg., vol. ii., No. 4. 

35. Progress Report on School Quininisation, Allahabad, 19 14, by J. D. 

Graham, I. M.S., Special Malaria Officer, United Provinces. 



APPENDIX 



THE CITY OF 

Singapore Municipality Monthly 



Year. 


January. 


February. 


March. 


April. 


May. 




1892 


34-36 


39-63 


27.64 


28-92 


27-35 




1893 


38.08 


32-54 


33-99 


35-24 


43-75 




1894 


33-7° 


28.99 


28-90 


29-08 


35-17 




1895 


32-35 


26-53 


31-43 


45-03 


51-50 




1896 


46-8 


44.4 


44.4 


54-5 


63-2 




1897 


41.9 


32-1 


38-8 


43-5 


46.8 




1898 


30.78 


26-41 


26-01 


28-48 


36.71 




1899 


37-58 


29.83 


33-H 


32.04 


35-93 




1900 


34-83 


29.19 


35-85 


36-53 


42.29 




1 901 


44-54 


34-42 


36-04 


40-55 


49-00 




1902 


46-25 


35-72 


40.87 


62.44 


85-31 




1903 


45-33 


44-66 


46-21 


44-66 


65.67 




1904 


36-59 


34-31 


35-94 


42.49 


54-83 




1905 


43-32 


37-91 


45-91 


43-74 


48.41 




1906 


36-86 


35-45 


41-54 


46-06 


40.76 




1907 


34-85 


26.95 


36-38 


42.49 


51-25 




190? 


33-77 


32-37 


37-82 


42-06 


56-00 




1909 


43-03 


2916 


31-86 


36-61 


42-69 




1910 


37-04 


34-30 


35-31 


35-31 


47-53 




igil 


40-07 


28.93 


36-37 


49-73 


So-ig 




1912 


40-26 


33-81 


35-02 


42.09 


50.32 




1913 


33-41 


25.91 


29.23 


31-54 


36-73 




1914 


33-65 


28.54 


31-14 


35-90 


42-15 




1915 


35-74 


28-48 


28.07 


26-00 


26-53 




1916 


24.32 


21-25 


23.80 


3i-o7 


36-45 




- 1917 


30.78 


30-27 


33-89 


34-28 


37-75 




1918 


39-68 


33-70 


33-16 


37-49 


45-31 




1919 


32-32 


26.50 


26.20 


27.77 


32-47 




8 


70 













APPENDIX 



SINGAPORE. 

Death Rates, 1892 — 1919. 





June. 


July. 


August. 


September. 


October. 


November. 


December. 




30-27 


33-98 


32-13 


27.14 


32-34 


30-84 


35-48 




44.IO 


38-08 


34-75 


3I-36 


30-94 


28-16 


34-74 




32-62 


38-47 


30-40 


28.38 


30-67 


31-55 


33-36 




72-54 


50-71 


43-20 


31-37 


38-95 


36-99 


44-5o 




54-3 


48.19 


49-51 


44-56 


44.24 


40-12 


37-26 




46-3 


49.1 


41.5 


42-2 


41.5 


34-7 


32-0 




39-76 


44-43 


39-94 


34-79 


34-91 


34-97 


39-76 




40-53 


37-04 


32.56 


30-35 


35-29 


34-42 


37-71 




46.41 


44-43 


40.65 


45-00 


40.76 


52-22 


50.81 




50-33 


50.50 


49.40 


44-66 


47.90 


50-10 


45-64 




61-82 


53-89 


40.42 


45.28 


47-55 


48-00 


47.21 




51-74 


48.59 


44-50 


46.27 


44.94 


42-62 


41.79 




43-77 


53-26 


53-30 


44.27 


45.68 


40.27 


45-73 




51-54 


5i-i6 


41.51 


35-10 


42.42 


39-39 


44-54 




36-86 


40-65 


32-54 


34-99 


38-10 


34-52 


37-05 




54-00 


53-75 


68-68 


50.85 


So-54 


44-99 


42-80 




51-06 


5o-3i 


49.46 


46-26 


50-11 


61-40 


50-81 




39-31 


37-79 


36-81 


41.56 


43-97 


45-00 


34-90 




43-68 


55-56 


50.56 


48.15 


44-59 


43-15 


39-54 




85.83 


60-27 


47-51 


44-14 


50-06 


44.28 


43-49 




55-96 


50-23 


44.42 


39-59 


37-89 


38-47 


36-05 




38-30 


38.26 


33-07 


33-24 


38-13 


36-16 


35-51 




40-62 


36-37 


31-56 


28-41 


33-52 


33-35 


34-n 




26-20 


25-95 


28-98 


25-83 


27.36 


24-13 


25-42 




34-55 


33-42 


30-59 


27.84 


29.70 


27.64 


3o-47 




38-73 


38.50 


38.58 


39-6o 


38-50 


33-81 


34-36 




44-55 


51-33 


35-27 


30-36 


69.05 


50.72 


34-35 




35-79 


38-44 


38.85 


36-17 


35-53 


35-6i 


35-79 



371 



2 C 



INDEX 



Alga, the "felted," 189, 190, 197 
Ampang and Ulu Gombak Water 

Works, 102 
Amritsar, deaths from malaria, 103 
Andaman Islands, convict settlement, 

79 
Ankylostomiasis, 89, in, 243 
Annals of Tropical Medicine and 

Parasitology, 129 
Anopheles, the, 5 ; breeding-places, 
13-16, 21, 24, 137, 215, 244 ; action 
of oil, 189 ; effect of drainage on 
different species, 213-216 
Anopheles aconitus, 186, 208-210, 221, 
289, 290, 362, 363 
aitkeni, 219, 221, 285, 287, 288, 320 
albotceniatus, 81, 284, 287 
auriroslris, 47 
barbirostris, 197, 200, 205, 208-210, 

215, 219, 221, 289, 290, 302, 363 
cos talis, 216 
culicifacies, 211 
fuliginosus, 14, 15, 197, 200, 203, 

210, 211, 215, 290, 363 
funesta, 211 
indefinita, 77, 78 
karwari, 87, 214, 216, 302, 324, 

33 2 
kochii, 205, 210, 215, 219, 221, 290, 

302, 3°3 
leucosphyras, 286 
ludlowi, 77-85, 216, 223, 244, 283, 

330, 361 
maculatus, 37, 59, 66, 67, 86-88, 112, 

121, 130, 131, 136, 159, 164, 168, 
174, 176, 179, 182, 186, 194, 197, 
2IO, 211, 214, 215, 219, 220, 230, 



3°2, 
362, 



:o8- 



179. 

221, 
308, 



246, 249, 253, 283, 289, 3OO, 
308, 324-28, 332, 335, 348, 
363 

Anopheles rossi, 77, 78, 197, 200, 
205, 208-211, 214-16, 219, 
284, 290, 302, 324, 363 

separatus, 215, 284 

sinensis, 139, 197, 200, 203, 205, 

211, 215,219,290, 302,363 
umbrosus, 46, 59, 60, 69, 79-81 

87, I3°> 133. 139. 159, 167, 
208-211, 213, 215, 216, 219, 
223-25, 246, 251, 283-90, 300, 
319, 320, 332, 346, 361, 362 

Ansley-Young, Dr, 249 

Anti-mosquito Ordinance, 331 

Ashley Combe, 93 

Ayer Running, 102, 20S, 210 



Bach, Mr, 136 

Bailey, W. W., 39, 40 

Ball, Mr, 272 

Bandjar, 220 

Banjarese, the, 160, 163 

Barbour, Dr Marshall, on Anopheles 

244, 283, 287 
Barker & Co., Messrs, 153 
Barlow & Co., Messrs, 153 
Batu Arang, 221 
Batu Blah Hill, 167 ; spleen rates, 

167 
Batu River, 293 
Batu Road Swamp, 227 
Batu Tiga, 32, 97 ; death rate, 142 
Batu Unjor Estate, 247, 249 ; cases of 

malaria, 249; spleen rates, 250 
Bendang Siam, 207, 208 



373 



374 



INDEX 



Bentley, Dr, 243; "The Human 
Factor in Malaria," 98, note 

Bentong, 220, 221 

Beri-beri Convalescent Hospital at 
Jeram, 257 ; use of gauze, 257 ; 
number of cases, 258 

Bhera, deaths from malaria, 103 

Bignami, Signor, 4 

Blackwater fever, cases of, 75, 87, 94, 
164, 182 

Blakan Mati Island, 332 ; cases of 
malaria, 332, 334 ; measures 
against, 332 ; cost, 333 ; results, 

335 
Bluff Road Valley, 308 
Boon Hean Division, 164 ; spleen 

rates, 165, 166 
Borrow pits, Anopheles in, 244 
Bosanquet, N. C. S., 56 
Brick drains, grading of, 273-76, 279 
Bristol Channel, 93 
British Administration in the 

Federated Malay States, 1 
Brockman, Sir E. L., member of the 

Malaria Advisory Board, 311 
Browel!, H. F., 174 
Bukit Gantang Valley rice-fields, 206 ; 

Anophelines, 208, 210; map, 

209 ; result of investigations, 

211 
Bukit Rajah Estate, 162 ; plan, 163 ; 

death rate, 166 
Bukit Rotan road, 36, 37 
Bukit Tebok, 206, 210 
Byrne, Harold E., 236, 248 

Campbell, Douglas, 40 

Canalis, Signor, 4 

Carcosa Hill, 295, 308 

Carey, E. V., 14, 19, 143 ; " Notes of 

Fever experienced upon New 

Amherst Estate," 96 
Carey Island, 83-85, 223 
Celli, Signor, 4 
Cellia kochii, 13-15 
Ceylon, failure of coffee planting, 42 
Changkat Jering, 206 
Changkat Jong Water Works, 102 
Cheras, 33 



Children, cases of malaria, 31-33. 44 ; 
of enlarged spleen, 48-76) 82 , 8 5> 
90, 145, 158-60, 162, 166, 169, 
172-76, 188, 207, 220, 224, 240, 
242, 248, 250, 251, 253, 254, 256, 
321-23 ; method of examination, 
340 ; effects of malaria, 96, 175 ; 
death rate, 96 ; result of taking 
quinine, 106 

Chinese, deaths from malaria, 97 ; 
employment in the Federated 
Malay States, 149, 365 ; number 
of dialects, 149 ; cost of tapping, 
150 ; cost of production of rubber, 
154 ; squatters, 326 

Chironomus, 187 

Christophers, Major, 79, 243; "The 
Human Factor in Malaria," 98, 
note 

Cinchona, Countess D'El, 4 

Cinchona, use of, 4, 342 

Cinchonism, 116, 118 

Clay-pipe drainage, 305 

Club Road Valley, 306, 308 

Coast Railway, story of a, 243, 352 

Coastal Hills, 46, 86, 222, 362 ; 
Estates, 88-91 

Coastal Plain, 46, 222, 361 ; Estates, 

47-73 
Coffee-planting, 42 
Contour drainage, 306 
Coolies, result of examination, 88, 

in; effect of malaria, 94-98 ; 

administration of quinine, 107- 

109 ; table of working days, no ; 

quinine pills, 116 
Craig, Messrs James, 261 
Crimping, prevention of, 364 
Cromer, Lord, on irrigation in Egypt, 

127 
Culex fatigans, 214 ; sztiens, 82 
Culicines, 82 

Cumberbatch & Co., Messrs, 153 
Cumming, C. Malcolm, Chairman of 

the Planters' Association of 

Malaya, 202 

Dalrymple, Lieut.-col. J., 128 
Damansara Estate, 173-78; spleen 



INDEX 



rates, 173-77 ; parasite rates, 
I73-76 ; death rates, 177, 178 ; 
measures against malaria, 178 

Daniels, Dr C. W., 40, 102; Presi- 
dential Address to the British 
Medical Association in Belfast, 
114; experiments with the tube 
root, 212 ; on malaria, 216 

"Darat,"the, 91 

Day, Mr, 184 

Death rates, 140, 142, 145, 339, 350-55, 
37°! 371 ; with spleen rate, 
variation of, 98-100 ; per mille, 
100 ; on public works, 102 ; on 
Estates, 102 

Delhi, deaths from malaria, 103 

Delmege, Dr, 205 

Derris elip/ica, 212 

Desvoidtz jitgrcensis, 1 5 

Dhoby ponds, 333 

Donaldson, T., report on North 
Hummock Estate, 160-62 

Drain, how it acts, 266 ; the pipe, 
268 ; cylindrical, 269 ; how water 
enters, 269 ; clay-pipe, 305 ; brick, 
grading of, 273-76, 279 ; contour, 
306 ; earth, 272, 279 ; hill-foot, 
272 ; stone, 268 ; V-shaped open 
concrete channel, 329 

Drainage, value, 127 ; subsoil, 134, 
160, 268 ; compared with oiling, 
192 ; cost, 192 ; effect on different 
species of Anophelines, 213-16; 
of land, 266 ; results, 267 ; of 
ravines, 270 

Dunkery, 93 

Durham, Dr H. E., 14 

Earth drains, 272, 279 

Ellerton, H. B., 16 

Estate "A," 47-49; " B," 49, 245; 
"BB," 69; "C," 49-56; "CC," 
outbreak of malaria, 240 ; cause, 
241 ; death rates, 242 ; spleen 
rates, 242; "DJ," 196; "E," 
49-56; "EE," 69, 84, 364; "F," 
49-56; "FF," 69; «G," 49-56; 
"GG,"7o; "H," 56; "HH,"70 ; 
" HW," 224 ; plan of, 226 ; " I," 



57; "J," 58; "JC," 199; 
7i; "JJJ," 69; "JM," 
"J s >" 224; spleen rates, 
"K," 59; "KK," 72; "L,' 
"LL," 72; "M,» 61 
73; "N," 61 ; "NN," 



375 

"JJ," 
198; 

227; 

' 60 ; 

"MM," 

73; "O," 



61 ; "OO," 72; "P,» 62; "PG," 
cases of malaria, 243 ; cause, 
244 ; death rates, 245 ; spleen 
rates, 245; "PP," 72; "Q,» 
60, 63; "R," 63; "RR," 88; 
"S," 251; "SA," 224; spleen 
rates, 225; "SC," 197, 200; 
"SS," 9 o; "SSS," 65; "T," 64; 
"TT," 71, 90, 121; "V," 65-67; 
"X," 67, 249; "Y,"6 7 

Estates, economic effects of malaria, 
104 ; cost of weeding, 105 ; mos- 
quito-proofing lines on, 258-60 ; 
health of the labour forces, 351 

Euquinine, 118, 178 

Europeans, effect of malaria, 94 

Evans, F. D., 238 ; member of the 
Malaria Advisory Board, 311, 
319 ; study of Anopheles, 312 

Exmoor, 93 



Famine, result, 355 

Federal Hill, 295, 308 

Federated Malay States, The, 1. See 

Malay 
" Felted " alga, 189, 190, 197 
Fens of Lincolnshire, 246 
Fiji Islands, disease of Filaria, 278 
Filaria, disease of, 278 
Filaria nociurna, 5 
Finlayson, Dr, 272, 279, 321, 322, 

339 
Fletcher, Dr, 218 ; report on malaria 

at Kuala Lumpur, 294 - 96 ; 

member of the Committee, 297 
Fraser, Joseph, 136, note 

Galbraith, Mr, 181, 183, 184 

Gerrard, Dr, 309 

Gibson, John, General Manager of 

the Tremelbye Rubber Company, 

134 



376 



INDEX 



Oilman, Mr, 189 

Glenmarie Estate, 195 

Golgi, Signor, 4 

Gombak River, 293 

Gorgas, General, 353, note 

Graham, Major J. D., 344 

Grant, Mr, 184 

Grieve, Norman W., 133, 136 

Gurgaon, deaths from malaria, 103 

Guthrie & Co., Messrs, 153 



Hacker, Dr, 80 ; on malaria, 283 

Hale, A., 36, 37 

Haron Estate, 251 ; death and spleen 

rates, 251 ; chart of macidatus 

wave of malaria, 252 
Harper, A. C, & Co., Messrs, 153 
Harrison, C. R., 172, 189 
Harrison & Crossfield, Messrs, 153 
Hendrie, Mr, 189 
Hickey, Dr, 260 
Highet, D. J., member of the 

Commission at Port Swettenham, 

24, note 
Hilly Estate, cases of malaria, 254 ; 

spleen and death rates, 254-56 ; 

cause of the outbreak, 255 
Hose, E. S., member of the Committee 

at Kuala Lumpur, 297 
Hospitals, screened, 261-63, 364 ; 

cases of malaria, 337-39 
Houses, screened, 260 
Hunter, Dr P.-S., 321, 357 ; at Blakan 

Mati, 332 



Indian coolie, employment in the 

Malay States, 147-49 ; system of 

recruiting, 148 
Indian Immigration, reports, 48, 98, 

102, 351 
Influenza epidemic, 140, 142 
Inland Hills, 46, 219, 222, 288, 362; 

Plains, 46, 229, 362 
Ipoh, 107 
Irvine, I., 136 
Italians, experiments on mosquitoes, 

6,9 



Jackson, J. E., member of the Com- 
mittee at Kuala Lumpur, 297 ; 
system of drainage, 298 

Jackson, R. D., 305 

Java, 365 

Javanese, the, 75 

Jelutong factory, 181 

Jeram, 34, 36 ; beri-beri convalescent 
hospital, 257 ; cases of malaria, 
257 ; use of gauze, 257 

Jugra, 3, 32 ; cases of malaria, 70, 
120, 179-81 

Jungle, mosquitoes of, 285 ; silent 
warfare, 291 

Kampong Jago, 321 

Kampong Paya, 208 

Kampong Quantan, 32 

Kapar, 32, 36 ; drainage scheme, 39 ; 
cost, 40 ; death rate, 352 

Karimon Island, 181-85 ; measures 
against malaria, 182-84; subsoil 
drainage, 183 

King-Harman, E. H., 51 

Klang, population, 7, 248, 351 ; area, 
7 ; number of cases of malaria in 
the hospital, 7, 25, 27, 32, 346; 
measures against malaria, 9-13; 
Anopheline breeding-places, 13- 
16 ; drainage scheme, 16, 1S-20, 
271-76; outbreak in 1901, 17; 
cost of the works, 19 ; deaths, 
28-30, 44, 350 ; cases of children, 
31, 44 5 plan of, 247 ; spleen 
rates, 248 

Klang Lands Estate, 251 ; River, 7, 
21, 63, 293 ; Water Works, 258 

Koch, Dr R., study of malaria, 5, 9 

Krambit, 220 

Krian Irrigation Padi Fields, 203 ; 
map, 204 ; health of children, 
205 ; Anophelines, 205, 210 ; 
result of investigations, 211 

Kuala Langat, 7, 34, 74, 179 

Kuala Lipsis, 219 

Kuala Lumpur, 32, 227, 229, 293 ; 
meteorological return, 3 ; lecture 
at, 217, 305 ; population, 293; cases 
of malaria, 294-96, r 3o8 ; Com- 



INDEX 



377 



mittee appointed, 297 ; report, 
298 ; criticism on, 298 - 300 ; 
attempts to exterminate malaria 
by drainage, 300-307 ; result of 
investigations, 301-304 ; Malaria 
Advisory Board, 310 ; plan of, 
311 ; system of drainage, 312 ; 
results, 313, 318; death rate, 
314 ; cost of works, 317 ; note on, 
318-20 

Kuala Medan, 220 

Kuala Selangor, 7, 34, 36 ; cases of 
malaria, 35, 346; drainage works, 
36-33 

Labour Force, wastage of a, 103 ; 

death rates, 351-54; problem, 

364-66 
Labuan Padang Estate, 173 
Lalang, 105 
Lanadron Estate, 91 
Land, drainage, 266 ; results, 267 
Langat Road, 32 
Larvacide, 186, 212 
Laveran, A., 4 
Lazaroo, R. W. B., 22, 113 
Leicester, Dr G. F., 179, 320; 

Citlcidce of Malaya, 13, 14 
Lincolnshire, the Fens of, 246 
Liquid fuel, 191 
Liverpool A nnals of Tropical Medicine, 

134 

Liverpool School of Tropical Medi- 
cine, 5 

Low, Dr, 6 

Lucy, Dr, Acting State Surgeon, at 
Port Swettenham, 22 

Ludlow, Dr Clara S., study of 
mosquitoes, yj 

Lynton, 93 

M , case of, 143 

Macaulay, Dr T. S., 45, 52, 54, 60 

Malacca, 32 

Malarco, 181 ; subsoil drain, 184 

Malaria, 3 ; history, 4-6 ; number of 
cases at Klang, 7, 17, 25, 27, 32 ; 
measures against, 9-13, 24, 76, 
128, 194 ; at Port Swettenham, 



2 3i 2 33-35 > death rates, 28-30, 
44, 98, 103, 339 ; cases of children, 
31-33 ; at Kuala Selangor, 35 ; 
on the Coastal Plain Estates, 47- 
76 ; in mangrove swamps, 81 ; 
due to Anopheles ludlowi, 82 ; 
effect on Europeans, 94 ; on 
coolies, 94-98 ; on children, 96, 
175 ; economic effects on an 
estate, 104 ; relation of dose to 
intensity, 119-25 ; value of drain- 
age, 127 ; of rice-fields, 212 ; out- 
break on Estate " CC," 240 ; on 
"PG" Estate, 243; at Batu 
Unjor, 249 ; on a Hilly Estate, 
254 ; at Jeram, 257 ; Memo- 
randum on, 271-81 ; at Kuala 
Lumpur, 294-96; cases in hospital, 
337-39, 346 ; the seasonal varia- 
tion, 344 ; in Singapore, 356 

Malaria Advisory Board formed, 309 ; 
members, 311 ; work of the, 312, 
316 

" Malaria, Some Clinical Aspects of 
Quartan," 43 

Malay States, The Federated, 1 ; 
British Administration in, 1 ; 
position and climate, 2 ; rainfall, 
2 ; death rate, 102, 355 ; employ- 
ment of Indian labour, 147-49 > 
Chinese, 149 ; estimated gain 
from sanitation, 156, 355, 359; 
Labour Force, 353, 364-66 ; cost 
of works, 362 

" Malay Peninsula, Certain Observa- 
tions in the Epidemiology of," 
2S5 

Malayalees, the, 164, 196 

Malays, the, characteristics, 213 

Mangkoewinoto, R. M. M., 79 

Mangrove forest, 80 ; zone, 46, 361 

Manila, 77 

Manson, Sir P., experiments on mos- 
quitoes, 5, 6, 9 

Mansonia annulipes, 14, 15 

Marchiafava, Signor, 4 

Mason, J. Scott, 234 ; Chairman of 
the Klang Sanitary Board, 134 

M'Closky, Dr, 294, 296 



378 



INDEX 



Menstruation, 115, note 

M'Ewan, John, 136,' note 

M'Glashan, B. P., member of the 

Commission at Port Swettenham, 

24, note 
Mian Mir, 319 
Miasma, theory of, 4 
Middleton, Dr W. R. C, 272 ; report 

on malaria in Singapore, 321, 356 
Midlands Estate, 168-73; subsoil 

drainage of South or Old Division, 

168 ; North Division, 169 ; plan 

of, 1 70 ; cases of malaria, 171; 

spleen rates, 172 ; death rates, 

172 
Millard, Dr, 234 
Mimosa pudica, 228 
Minehead, 93 
Morphia, 117 
Mosquito nets, failure, 261 ; reduction, 

361 
Mosquitoes, researches on, 5 ; sting, 

66 : measures against, 76 ; species, 

77; breeding - places, 81, 283; 

discrimination in water, 201 ; 

classification, 282 ; of the Jungle, 

285 ; of stream courses, 286, 289 ; 

of ravines, 287 
" Mosquitoes of Stream-courses," 231 
" Mosquitoes of Virgin Jungle," 285 
Muir, Mr, 187; attacks of malaria, 

188 
Myzomyia rossii, 13 
Myzorhynchus barbirostris, 14, 15 ; 

Marwari, 13; separatus, 15, 16, 

210, 284; sinensis, 13-15; um- 

brosus, 13, 14, 15, 210 

Negri Sembilan, 211, 213, 218 

Nets, mosquito, failure, 261 

New Amherst Estate, 96, 143 

New Seafield, 139 ; labour force, sick 
rate, 345 

Niven, Dr J. Lang, 37 

North HummockEstate, 157; Division 
A., 157; B., 158; C, 159; sub- 
soil drainage, 160 ; report on, 
160-62 

Nyssorhynchus nivipes, 14, 15 



Observations on Malaria, 129 

Oil spraying, 332 

Oiling an estate, system of, 186 ; 

result, 188 ; its action on larva;, 

189 ; application, 191 ; cost, 191 ; 

compared with subsoil drainage, 

192 ; advantages, 192 
Opium, 117 
Orme, Dr Bryce, 208 

Padang Jaw a, 32 

Pahang, 213, 219 

Palvval, deaths from malaria, 103 

Panama, system of subsoil drainage, 
134, 135 ; measures against mos- 
quitoes, 186 ; result of the work, 
353 note, 359 

Parasite rate of Damansara Estate, 
173-76 

Parkes, Josiah, 269 

Penang Quarantine Station, 351 

Perak, State of, 3, 213 

Permatim Pasir, 179, 180 

Petaling Hill, experimental drainage 
works on, 304 

Philippine Islands, 77, 80 

Pipe Collars, 269 

Pipe drain, 268 ; the cylindrical, 269 ; 
how water enters, 269 

Pitchakawa Estate, 253 

Plague, 278 

Porlock Weir, 93 

Port Swettenham, 3, 21, 223 ; sanitary 
measures, 22 ; opening of the 
Port, 22 ; outbreak of malaria, 
2 3> 2 33-35 ; cost of the works, 
24 ; area reclaimed, 26 ; deaths, 
28-30, 350 ; cases of children, 33 ; 
of influenza, 142 ; oiling at, 186 ; 
population, 234, 240, 351 ; criti- 
cism on the drainage scheme, 235 ; 
general level, 236; extension of 
the bunded area, 236 ; quarantine 
station, 237 ; plan for the drain- 
age of the new area, 237 ; 
estimates, 238 ; section through 
sluice, 239 

Pratt, C. H., 218, 222 ; investigations 
on Anopheles, 297 



INDEX 



379 



Prince, Le, 135 

Proceedings of the Imperial Malaria 

Conference at Simla, 103 
Proto-anopheles, 288 
Pseudo-myzo?nyia rossii, 1 5 
Pulau Tawa, 220 

Punjab, deaths from malaria, 103 
Pyrexia, cases of, 43, 106, 341 

Quartley, H. R., 135, 138 ; member 
of the Malaria Advisory Board, 

3ii 

Quinine, use of, 4, 58, 63, 88, 97, 99, 
322, 342, 344, 363 ; effect on the 
birth rate, 96 ; administration, 
106-113, 115, 129; limitations, 
113, 128, 136; dose, 115, 117, 
363 ; time and form, 1 16 ; relation 
of dose to intensity of malaria, 
119-25 ; ill-effects, 125 ; case of 
blindness, 125, note ; cost of 
administration, 126 

Quinine sulphate, 1 16-18 

Quinine hydrochloride, 117 

Radin Mas ravine, 324 

Railway, a Coast, story of, 243, 352 

Rasak Estate, 189 

Rattray, Dr, 91 

Raub, 220 

Ravines, breeding-places of Ano- 
phelines, 124, 324 ; drainage, 
134, 270 ; danger of opening, 
218, 288 ; mosquitoes of, 287 

Read, H. J., ix. 

Reeve-Tucker, W. S., 187 

Rice-fields, 212, 363 

Rivers, tidal, 223 ; non-tidal, 224 ; 
still farther inland, 227 ; the 
smaller, 229 

Robson, J. H. M., member of the 
Malaria Advisory Board, 311 

Ross, Sir Ronald, preface to "The 
Prevention of Malaria in the 
Federated Malay States,'' ix.-xi. ; 
on malaria, 5, 9, 129, 319; Pre- 
vention of Malaria, 124, note 

Rubber industry, 42 ; cost of pro- 



duction, 105, 152-56; of weeding, 
105, 152 ; of tapping, 150, 155 ; 
renewal of bark, 151 

Rural Sanitation in the Tropics, xiii. 

Rutherford, H. K., 136, note 

Sabak Bernam, 36 

Sakais, the, 69, 83 

Salonica, 128 

Sambon, Dr, 6 

Sansom, Dr Charles Lane, Principal 
Medical Officer, 309 ; Vice- 
President of the Malaria Advisory 
Board, 311 

Sawahs, 202, 211 

Schuffner, Dr, 80 

Screened Hospitals, 261-63, 3^4 ; plan 
of, 263 ; houses, 266 

Screening, experiments with, 257-63, 

364 
Seafield Estate, result of quinine 
administration, no; area to be 
drained, 130 ; plan of ravines, 
132, 141 ; engineering problem, 
133 ; system of subsoil drainage, 
134-36 ; scheme approved by the 
Directors, 136 ; first pipes laid, 
136 ; Old or Southern Division, 

138 ; New or Northern Division, 

139 ; results from the drainage, 
140, 147 ; influenza epidemic, 140, 
142 ; death rate, 140, 142, 145 ; 
children, 143, 144 ; spleen rates, 
144 ; cost of the subsoil drainage, 
154 ; estimated gain, 156 

Selangor, 87 ; Coast Districts of, 34 ; 

Medical Report, extracts, 34 ; 

Administration Report, 97 ; 

Drainage Rate Enactment of, 

128, note 
Selvvorthy, 93 
Sepang, 32 
Serapong, 333 
Seremban, 1 1 
Sewage, system, 274 
Sibolga, 79 
" Silt pit," 290 
Sime, Mr, 134 
Simpang, 207 



380 



INDEX 



Singapore, 355 ; memorandum on 
malaria, 271-81 ; measures 
against, 321, 356 ; population, 
356 ; death rates, 356-58, 370, 371 

Sleeping sickness, 278 

Smith, Hammond, 253 

Soil, composition, 264 ; water in, 265 

Solbe, Mr, 195 

Spleen, cases of enlarged, 48-76, 82, 
85,90, 145, 158-60, 162, 166, 169, 
172-77, 1S8, 207, 220, 224, 240, 
242, 248, 250, 251, 253, 254,256, 
321-23 ; method of examination, 
34o 

Spleen Rates, 98-100, 144, 158-60, 
162, 165, 166, 169, 172-77, 34o 

Spooner, C. E., member of the Com- 
mission at Port Swettenham, 24, 
note 

Sporozoites, 112, 137 

Spottiswoode, 330 

Sprayers, 191 

Stanton, Dr A. T., 66, 283, 308 ; 
examinations of coolies, ill j 
report on the Seafield Estate, 
137 ; experiments on Anopheles 
aconitus, 211; member of the 
Malaria Advisory Board, 311 

Stegomyia scutellaris, 285 

Stevens, Mr, 341 

Stone drains, 268 

"Stream - courses, Mosquitoes of," 
231, 286, 289 

Strickland, Dr C, 80, 81 ; researches 
on malaria, 218 ; discovery of 
the "Inland Hills," free from 
malaria, 219, 222; "The Mos- 
quitoes of Stream-courses," 231, 
286 ; study of mosquitoes, 283, 
315, 320; "The Mosquitoes of 
Virgin Jungle," 285 

Studies from the Institute for Medical 
Research, 181 

Subsoil drainage, system of, 134, 160, 
268 ; compared with oiling, 192 ; 
cost, 192 

Sumatra, 80 

Sungei Binjai, 162 

Sungei Kurau River, 203 



Sungei Merah River, 203 

Sungei Rasak Division, 166 

Sungei Way Estate, result of oiling, 
187 ; death and spleen rates, 188 

Swamp, filling up a, 276, 280 ; drain- 
ing, 328, 335 

Swellengrebel, Dr N. H., 79, 80 

Swettenham, Sir Frank A., ix.; History 
of British Malaya, 2 

Sydenham, Dr Thomas, " History and 
Cures of Diseases," extracts from, 
342-44 

Taiping, 307 

Tamils, the, 75, 84, 164 ; character as 
labourers, 147 ; cost of tapping, 
150; disadvantages, 151 ; advan- 
tages, 152 ; cost of production 
of rubber, 154; effect of famine, 

355 
Tarentang Estate, 230 
Telegu coolies, 172 
Telok Batu Estate, 173 
Telok Blangah, cases of malaria, 321 ; 

measures against, 322, 327 ; 

results, 335 
Tembeling, 219, 220 
Theobald, Mr, 77, 79, 282 
Thornley, Dr, 296, 297, 301 
Tras, 221 
Travers, Dr E. A. O., 16, 258, 294 ; 

member of the Commission at 

Port Swettenham, 24, note 
Treacher, Sir W. Hood, 40 
Tremelbye Estate, 249 

Ulu Julei, 220 

Venning Road Valley, 308 
Veraltina butleri, 15 
Vogel, Dr De, experiments on mos- 
quitoes, 78 

Walker, R. K., 160 
Warburg's tincture of quinine, 117 
Ward-Jackson, C, xv. 
Wastage rate, 99, 101, 103 
Water, breeding-place of mosquitoes, 
201 ; altering the composition, 



INDEX 



381 



202, 213, 363 ; in soil, 265 ; lines 
of movement in drained land, 266; 
how it enters a drain pipe, 269 

Watkins, A. P., member of the Com- 
mission at Port Swettenham, 24, 
7iote 

Watson, Dr Malcolm, preface to 
The Prevention of Malaria in 
the Federated Malay States, 
xiii. -xv.; District Surgeon of 
Klang, 7 ; measures against 
malaria, 9-13, 165, 182, 230, 322 ; 
drainage scheme, 16, 134 ; report 
on sanitary measures for Port 
Swettenham, 22 ; member of the 
Commission, 24, note ; receipts, 
31 ; examinations of children, 31, 
44, 180, 205-208, 229, 248 ; District 
Surgeon of Kuala Selangor, 35 ; 
report on road drainage, 39-41 ; 
some clinical aspects of Quartan 
Malaria, 43 ; examinations of 
coolies, 88, 1 1 1 ; riding tour, 93 ; 
address on quinine administra- 
tion, 107 ; attacks of malaria, 119; 



at Panama, 186 ; on the value of 
oiling, 187 ; visits a Tamil settle- 
ment, 202 ; lecture at Kuala 
Lumpur, 217, 305, 319 ; researches 
on malaria, 217 ; on leave, 235 ; 
in charge of Jeram Hospital, 257; 
memorandum on malaria, 271-81; 
criticism on the experimental 
drain at Petaling Hill, 305 ; 
member of the Malaria Advisory 
Board, 311 ; note on Kuala 
Lumpur, 318 ; report on malaria 
in Singapore, 323, 326, 330; 
method of examining children 
for enlarged spleen, 340 ; estates 
under his care, 351 

Weeding, cost of, 105, 152 

Wellington, Dr A. R., 218; "The 
Malaria of Kuala Lumpur,'' 222 ; 
report on, 293, 314 ; at Taiping, 

3°7 
Wright, H., member of the Com- 
mission at Port Swettenham, 24 

Zygotes, 112, 137 



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